Honey... end it. Don't go back to him. Even if he can change, it's not going to happen unless he HAS to, unless he loses something important. If you go back to him, it'll just mean that he doesn't HAVE to change.

You deserve SO much better than that.

About the sexting and nude photos- You must have been feeling terrible pain. You must have been feeling so unworthy, that you felt that you needed others to make you feel worthwhile and beautiful. I am sorry you ever felt like you needed that. You are worthwhile and beautiful- hold onto that. Don't beat yourself up about it, and don't let other judgmental people make you feel bad about it. Giving you a hard time about it will not help, and listening to them won't help either.

You absolutely owe him NOTHING. He doesn't deserve you. The way he has treated you is NOT OK, and he doesn't deserve any more chances. Let this help you grow. Get counseling. Don't let this break you. Leave him behind and don't look back. You deserve better.