Don't let yourself get sucked in any more. The answer to everything is "You need to seek help, stop seeing OW, and get yourself straight first before we can discuss our relationship." And meanwhile, nothing you are doing is any business of his.
He'll have temporary fits because you aren't waiting on the shelf as Plan B. OW will be pulling him her direction. You don't need to be abused by him, so don't let him pull you into arguments. "I'm sorry you feel that way " is a good response for most things. Definitely don't put anything in written form that you wouldn't want read in a divorce court.
