I think I know how you feel. I'm certainly less than I'd like to be, and I haven't been especially successful in life, but here's one thing that seems to help: I try to maintain interests in some things that have nothing to do with anyone else, and which also have nothing to do with "success" (the sorts of things no one ever has a chance to judge me about). For example, I draw (not very well!) and write poetry (even worse!), and I always keep these things to myself. I enjoy them, they make me feel a little better, and it doesn't matter at all what others think, because they never see it anyway. Sometimes, if your public life isn't treating you well, one answer is to try to expand your private, truly private life. Do you have any private hobbies of this sort? Do you like to read, for example? To write? To draw? To play music or listen to music? and so on? I'm actually interested.
I hope this doesn't seem like ridiculous advice!