I really think you should block all contact with him and literally never speak to him again. If he tries to come back into your life, do not let him, and if he ever forcefully tries to reenter your life, get a restraining order. This man sounds really dangerous.

As for the need for closure, that’s just something our minds THINK we need to move on, but we don’t actually need it and you can move on without it. Just look at his behavior so far. There really isn’t anything he can tell you that is going to make what he’s done feel better or even okay, and it will likely just make you feel worse… so I would write down, on a  list, everything he has done that has been abusive or unfair and that you do NOT want in a boyfriend and use that list as your closure. Read it every time you start feeling bad or feeling like you need to talk to him. Most of all, be patient with yourself and give yourself time to detach.  You may have had a rocky relationship, but you still have an attachment to this man, and it will take time for that to dissolve and that is normal. But in order for you to be able to let go and move on, you have to distance yourself.