Probably you have irrational memes that are preventing you. They make you feel bad and ashamed to be wrong, they make you feel attacked by criticism, they make you feel attached to your ideas, and they make you blind to their existence, and sometimes blind to the fact that you are not in fact acting in the rational way described above.
I can say this without knowing who is reading because such memes are ubiquitous in our culture. You are not alone. You are not a rare person with an unfortunate difficulty. It is like that for everyone. That can be hard to accept because it means if people do better *that could have been you* -- there was nothing fundamental to stop you. So it is *your fault* that you are doing worse than they are. But as much as taking responsibility for your failures can be hard, it is worthwhile. It means you recognize you can do better; denying that would be a huge obstacle to improving. And it means taking responsibility for your successes: having pride in what you have achieved, and seeking to do more.
But what exactly should you do tomorrow to start making progress? Here is one approach, which is by no means the only one.
One place to start is by changing your sense of identity. Ideas which you no longer believe *are not part of you*. If you are proven wrong, but change your mind, then suddenly *you are not wrong anymore*. Criticism isn't about making you wrong, which you'd want to deny. It's about giving you the opportunity to not be wrong anymore; to abandon the wrong parts.
Even ideas that are still within you do not necessarily deserve any respect. If you don't like one, but it's hard to change, whatever: screw it. *It's not you*. It's just some nasty intruder who has taken up residence in your mind. Don't let it be part of your identity. Don't feel ashamed of it. Don't defend it. Don't act on it. Just attach your sense of identity and self-worth to only a smaller, better part of your mind over which you have control. (And really, who can fault you for refusing to feel bad about things over which you do not have control? If you don't control it, it isn't your fault. You may have made mistakes in the past, but the current version of you hasn't.)
The most obvious thing that will go wrong with this is your emotions. You'll feel bad anyway, or feel weird, or still feel defensive about parts of you which you don't respect intellectually, or feel guilty. Screw them. Emotions are largely bad. They are the tools of your memes. Just ignore them. They have no power over what actions you take in your life. They don't move your limbs around. They do not control what words you say. And they do not control what you think is true.
Don't repress emotions. You don't want to be in denial about having them. Just disrespect them. They aren't the boss of you. It's like if you are into sports and you feel some physical pain. If it's nothing medically dangerous, then you don't respect it. It's just your body being annoying. It is part of your environment, just like emotions. Not your fault. You just keep playing.
Acknowledge emotions. They exist. Take note of them. But don't act on them. They aren't reasons. And don't take them personally. You didn't choose to have this emotion (just now; maybe it's due to your choices long ago.)
"Don't live life through gritted teeth," is good advice. You don't want to settle into a permanent routine of having this sort of conflict in yourself. But nor do you want to surrender. What you need to do is win. And take pride in your struggle to do so. Don't grit your teeth. Shout your defiance.
Bad emotions won't stop occurring overnight. The easiest cases should take a few days at least. Most cases will take more like six months, and harder cases won't be complete for years. Times can vary tremendously, but I think ballpark estimates are more useful than nothing. One thing you can see is you shouldn't give up quickly. And after two months is giving up quickly.
Success and progress are different. Progress can come fairly soon. But usually after a few attempts there appears to be absolutely no progress. And this is disheartening. But then not too long after you break through and it gets a bit better.
What does an attempt look like? You feel an emotion. You notice it. It can take a while to learn to notice them, and figure out what emotion it is. You look at it dispassionately. You get perspective. You don't act on it. You think about why the emotion is not reasonable, and think you don't want to have it anymore (you can do this while reflecting later at first). You think about what would be a good attitude to have. You think about what the best thing to do is, according to reason, and you do that, even though you don't feel like it. And then you feel proud and good, or at least at first you think you have reason to be proud and to feel good.
In abstract terms, what you are doing is putting your emotions and memes into a very hostile environment, hateful of them even. And in that environment they cannot function properly, and over time they change and evolve. You can't control them directly, but you can take attitudes about what sorts of emotions and memes are acceptable to you, and harass anything that doesn't qualify until your unconscious mind manages to sort out all the details and change it.
You may feel dumb at first having this emotion you don't want and not knowing how to get rid of it. And every time you feel the emotion, you feel dumb or silly. The emotion is dumb. Your lack of control is frustrating and is in part a lack of skill on your part. But trying to accept or reconcile with the emotion is no good life. That makes you a slave to it. This feeling dumb is hard on the meme/emotion too. It has trouble existing in that kind of environment. You know it's dumb. That means it is struggling. You're making progress! Be glad. As things move along the emotion will persist for less time, and eventually it will just be short flashes (stay aware! stay alert! notice these flashes. if you stop noticing and giving them enough thought to keep them in a hostile environment, they'll never go away). as you gain more distance from the feeling, you can laugh at it, or scoff. it's just this evil thing and it's dying. it has less and less power. your blindness is already gone. you can see it for the dumb thing it is. and now it's getting more and more painfully obvious every time it comes up. great! you are stronger than it.
you need to keep a positive attitude, and keep your optimism. memes can be beaten. emotions can be changed. you know this is true intellectually. but also you can develop emotions so that you feel it. if you're going to have emotions, put them to good use. instead of figuring out what causes good feelings and then doing that (ie, being the slave of your emotions) figure out what is worth liking and then start enjoying it. every time you do it, think about how lovely it is. take steps to make it a positive experience. soon you'll look forward to it.
a lot of this can be done in your head. do thought experiments. imagine the situation and then try to question parts of it or imagine acting in ways you'd feel bad about but think are good. if it's too hard feel free to stop for now, not because you are giving up, but just because you have a life to live and you don't need to do everything at once. just make more attempts. even if progress isn't visible every time it's still happening. when there is a breakthrough all those previous attempts with no obvious results did play a role. and you are learning about your own temperament. that's good too. understanding yourself makes everything easier. it makes it easier to be aware of your emotional state. it makes it easier to find the weak points of the emotions. it makes it easier to brainstorm attitudes you could take that would improve matters.
so, thought experiments. they are low risk. low cost. easy to abort. fast. less pressure to hurry. more control over setting up just the right situation. and it's not as personal. you are thinking about how you would feel in a situation instead of being in the situation and feeling it. and you start wondering why, and trying different things to see which cause you to change how you feel for the better. and as you gain skill, you gain control, and then you win.
it is unfortunate that all this should be necessary. I sympathize. I really do. memes are nasty buggers. they hurt you. they are evolved to be good at hurting you, and to be hard to get rid of. but it's worth fighting them. it's the only way to live your own life. it's the only way to control your life and have free choice. and it's the only way not to pass the same memes on to your children (which is done in large part by hurting your children in certain ways).
remember: you are creative, and your memes are not. yeah they contain a lot of knowledge. but they don't have a creative mind like you. if you put them into an environment they don't already have knowledge about they won't be able to adapt. so there is plenty of reason for optimism.
Static memes are like a hostage situation. They hold your emotions hostage. The options are to meet their demands, or to storm the building and probably lose some of the hostages.
Yeah it sucks. But the damage was done when the memes took over the building and grabbed all the hostages.
The demands memes make include finer control over your emotions (ie, more hostages, more weapons, a larger zone around the building where the police can't come, a new building even with satellite TV, etc)
Don't negotiate with terrorists. Don't succumb to emotional blackmail.
Do you feel bad about being fat? You shouldn't identify with your body. It isn't your mind. It's not the real you. It's part of your environment. Don't take it so personally. The only good reason to feel bad about being fat (besides increased risk of death) is that it indicates you have made bad choices: you failed to choose ways of eating that would achieve your goals. That lack of skill is an aspect of your mind. (But still, don't feel bad. Acknowledge your defeat and brainstorm an improvement in how you approach eating.)
By the way: just don't eat when you aren't hungry. That's all there is to it. It sounds hard to believe, but hunger evolved to keep humans fit and our body has powerful mechanisms to keep us from being overweight. Getting fat takes a lot of effort. Stop putting in the effort -- stop working hard against yourself -- and you won't be fat for long.
This still sounds hard to believe. Most people think they don't eat except when they are hungry. But those same people eat an entire plate of food at dinner time. All at once. So how could they possibly know if they were full already when they ate the last few bites? You have to wait a while to find out.
People also compulsively finish their plate even if they feel full. All the time. (Just like their parents forced them to do when they were younger. And like they will force their own children to do.) If you always finish your plate you have no idea if you are eating the right amount. You need to try other amounts to compare.
Many people fear "snacking". The real issue here is they aren't very aware of what they eat, so if they eat snacks and don't pay attention (common) they end up eating a lot while not hungry, and then they still eat meals (because people eat those without being aware of whether they are hungry. it's also just a habit.)
people also eat "comfort food". again that is eating when you aren't hungry. it might be worth doing to improve your mood, but don't claim you only eat when hungry if you do that.