Just to let you know, the whole thing where you look back on every little thing you do and cringe won't magically go away when you're an adult.
That's a self-esteem thing, not a teenager thing.
I guess what I'm saying is that this is one of those things that can get better, but won't just magically get better on its own. It didn't get better for me until I got some control in my physical health (stuff that would affect my perspective) and took agency in my mental health.
If you're in the situation to do so, check out what kind of therapy resources are available to you. You can just try a bunch until you find one that really clicks, and a lot offer free brief consultations.
Many employers offer 4-10 free visits for any immediate family members/offspring, too!
I'm sorry you feel so critical of yourself all the time. Its so draining to live like that.