Abusers always make those kind of promises! God does not want people abusing others. No one HAS to go through that! Maybe the bipolar does have something to do with it--but he still has to take repsonsibility for himself. Perhaps he can't do it right now, but you do NOT need to stay there and take it.
You deserve better than that!!! I know it's not that easy to get up and leave, but you need to get out of there! It's not gonna get any easier if you stay.
I was very abusive to other people--and even violent. I believe that my mental illness had a lot to do with it. But I have still had to take the responsibility to get myself better so I would not continue to hurt people. Of course, I want people to understand me, but it is not fair for other people to have to put up with my abuse, just because I'm having issues. I know it is your business, and I don't know you; but I have been through it myself, and have put other people through it, and have seen a lot of my family members be abused by other people that they loved, so the thought of someone going through that kind of breaks my heart. I just really hope you reconsider.