My husband is bipolar. I'm still with him

he was very physically and emotionally abusive. I guess about 4 yrs ago I found out he cheated but over the next few yrs I found out he had cheated our whole relationship. The physical abuse became very very violent after I found out about his cheating and he had to move out and do a year long batterers program. He doesn't seem to understand that as much as I love him he is my trigger. I have been with him since I was 17. I don't know who I am as an adult because my actions have always been controlled. We have 4 kids 18,16,14 & 3. I can't make it on my own. I have ms and make little income on disability. I have no close family that's alive. I'm stuck and everyday my mind and body is stressed. He says he has changed and is now medicated and in therapy but the damage to me is sever. I have to be strong because of my kids but really honestly I'm crazy on the inside now. I needed to vent and get this off my mind. I hate him and I hate myself for not leaving the first time he hit me or the 50th time he choked me out. I'm tired.