Perfectionism can be a huge part of it. I think it's something that you can recognize things like you want everything to be perfect, and also that you are going for an unachievable goal. Nobody could achieve that goal, right? So you could ask yourself why you expect something of yourself that is so unrealistic, and that you wouldn't expect of anyone else. You also have an incompatible goal, to be okay. Which one is more important? You can't do both, so you have to choose. And remind yourself of the choice that you made.

I don't recall if you are in therapy or not, but this stuff is often just too big for us to try to take on all by ourselves, and there is nothing wrong with getting help from someone who knows what to do about it and can help you discover and work towards your true goals so that you can be you, and not be controlled by thoughts that aren't you and that hurt you.