Well... I'm 70 years old now.
And I'm still affected by things that happened with me when I was a kid. I guess some people get past all of this sort of stuff... perhaps via therapy... or just because of their own personality make up.
I don't know why one person manages to bounce back & another just doesn't. I know I never will. I also know I'll never understand what it was all about either. It's just a ball of wire that will never be untangled. And I don't know how possible it is, or how important, to figure all of that out. My personal perspective is that, at some point, one simply has to put all of it behind oneself & move forward as best one can.
Here are links to 3 articles, from PC's archives, that talk about feeling worthless or like a failure & what to do about it:
When You Feel Worthless
Feeling Worthless and Depression
Here's Why you Feel Like a Failure + 10 Facts you Should Know | NLP Discoveries
My best wishes to you...