Look, I'm going to post a letter from my dad here. It's kind of long, but it's great advice for how to have an adult relationship with a parent who has always bullied you. It has to do with setting boundries right now so that you can cultivate a current relationship without putting yourself at their mercy in any way whatsoever. It won't help you figure out how to forgive or heal the past, but it will help you deal with a bully if you want to have a relationship with them right now. And then I'm going to post a wiki-link to an article called a something drama triangle which is kind of a cool theory.