You know it sounds like you've experienced more than "criticism" there. To me it sounds more like bullying or people being verbally abusive to you?? Now if that's the case it would be TOTALLY understandable for you to be sensitive when you hear something that might be construed as negative.
It may help if you put the past more into perspective?? From what I'm seeing you've either taken on board what people have said or still hurting from it??
Well you know that just because someone has said something doesn't make it true, right? And it's their weakness in needing to do that/make someone feel like that for whatever reason. It's not about you it's about them. And if they are like that they deserve absolutely no importance in your life. I know sounds simple BUT..........BUT true!!
As for criticism (constructive criticism) I'd say it's a GOOD thing, we can always use that as a new outlook to consider making changes we might actually want. We might decide to ignore it but then it's down to individual preferences isn't it?
As for other criticism, well that's going to happen regardless and a some of that might happen because people don't actually know YOU, haven't seen the bigger picture, not really worth much in that case then is it?
Other criticism, well you DO have the choice to ignore it and just leave it where it belongs. Then again if we were never criticized the real positiveness we feel from others making us feel good might not be quite so strong and that can be so good can't it (just a thought).
As for wanting to be perfect though you're running along the lines of living your life mostly for others, to please others, to "fit in" and to me that's got to be a major "No!". Seriously, it is much more important to be yourself, to be comfortable/happy being yourself and to be respected, valued, liked (if not by everyone!) for being yourself. You really do deserve to be YOU and to be true to yourself.
Best wishes
Alison