In my experience... You just have to keep trying. It hurts, it's hard, and you'll feel like a failure. But you'll survive, realize it wasn't so bad, and try again. You have to just keep pushing yourself. I also think having a therapist to back you up helps.

I'm sorry I don't have better advice. I've been struggling with this for almost a decade... But the people closest to me, tell me I'm getting better and that I'm slowly reaching my goal of getting my bachelor's degree. I'm just taking longer, and a different route, than most students. But that's okay. Because I"m not most students. I'm me, and I have to do what is right for me. And that is to keep trying, even though, in my eyes, I keep failing. Because one day, I will succeed.