One word - counseling.

If you look back to other relationships, or the way your parents treat each other, you'll probably see a pattern. The only way to break the cycle is with help, and a professional counselor is probably the best route. One of the first questions the marriage counselor asked me and my XH was "are your parents divorced?" Indicating that we didn't necessarily learn healthy relationship skills.

I learned a lot in my sessions, and even though we still got divorced, I know the sessions helped me in my overall people skills.

Secondly, don't beat yourself up. It takes two to mess up a relationship. One person isn't 100% wrong, and the other 100% right. You do have to learn that the other person is entitled to their feelings. And you need to learn to fight fair - "I feel that, when you say XYZ, it puts me down." Which is different than "stop treating me like a child."

If he wants to come back then, both of you should go to a counselor, together. If not, then you really ought to go anyway. Most people see counselors for a few sessions, not the Woody Allen thing of a life time of seeing their therapist. Mine would give me homework assignments - things to read - and we'd discuss them either next week or in two weeks.