How do you know when to hang on and when to walk away?

I have a long pathetic sob story no one will want to hear, but I finally thought I had found the one, after a long line of mistakes. I have always been afraid of commitment, and I have deep trust issues for good reasons, but I’ve been so happy in my latest relationship, so I finally jumped like I never have before. Turns out, he has some issues of his own I didn’t know about until last night. How do you know how much is too much?

When the issues cause hurt to you or others. What issues are they?