I would submit that this is an enormously difficult process that takes a whole hell of a lot of work to stop.
It may be the case that this isn't actually what's happening though, and I actually suspect that it is not.
These are just my theories and could totally be speaking out of my armpit. For whatever reason I feel very confident expressing them (rightly or wrongly).
Many people are really shitty people to have around you
Alternately, what can happen is that you are experiencing all the feelings implicated in surrounding yourself with the kind of people who would rather just call you names rather than show you how you're wrong. You're feelings in that case are telling not that you are a bad, dumb, immature or whatever, but rather that you need to get yourself away from people who actually are immature and dumb and bad. You feel what they choose not to feel.
It's painful to be around people who attack you for telling the truth. As it should be. It would be a problem if it wasn't.
The way to not take shitty things personally
If rather the problem is taking things personally and finding it difficult to feel a sense of certainty about what is valid feedback or not, the solution is both very simple and very difficult. It's living a strictly principled life.
What you base your own sense of self worth on are actually valid principles that you've reasoned through and accept with certainty because you've practiced living them in your own life. That's how you've been relating to yourself, with reference to good values.
The pretenders to the throne
I think we all kind of know this deep down, because there is a tendency for many people to fake like they are already at this point, like those people who pretend to be above it all. What they are really doing is they reactively reject things that make them feel bad and then invent some reason why they should reject it after the fact. They are not actually basing their own worth on principle, but pretentiously invoking principles to shut you up.
Also, these types of people tend to attack others who are actually demonstrating an understanding of living in accordance with principles because they know deep down in contrast that they are lying to themselves. And they use that after the fact justification machine to maintain their own narcissistic bubbles to attack the truly principled. And worse, always under the pretense of virtue (that they actually lack).
People who don't know enough about virtue, and those people who use similar justifications can end up idolizing these fakers. And that's why politicians and priests can have power in this world.
There is no silver bullet
You and I and everyone else I know of (save for a tiny few) have been abused or neglected as children, and (I believe) we will always be susceptible to things that would serve to trigger the complexes around our traumas. And people who come up with shitty ways of defending themselves and attacking others seem to be great at finding something that'll hook into you.
I've noticed that with a lot of work we can become less susceptible over time, but I'm not sure that it ever fully goes away. I don't know...
This problem is why there is a show like FDR
And books like the Psychology of Self Esteem, and lots of other great resources on philosophy, personal freedom and self knowledge. There are so many ways that people have been able to manipulate language and pervert the true meanings of so many of the concepts we use. It's a real battle to be able to combat these things not only in the people in our lives and in society at large, but also within ourselves.
Hopefully the pursuit of philosophy should be to gain the tools to enable yourself to be a better more effective person in a distorted and potentially dangerous world.
I talk a good talk sometimes, but actually living a principled life is super difficult and the people who do that work really impress me, and I can't help but feel respect and admiration for people who do the work.