You have all of the information you need about him....childish, vindictive, verbally abusive, etc., etc. etc. I know how difficult it is to not respond to his "crazy-making" behavior; but it can be done. Every time you respond to his craziness, you have HIM control over you, and that is what he wants. He can't argue by himself. You wouldn't go into an insane asylum and have a conversation with those people. Think of him as mentally ill and try to stop responding. I think I told you about the book which saved my sanity: The Verbally Abusive Relationship by Patricia Evans. 1 in 3 women will be physically assaulted and it all begins with verbal abuse.