There is only one possible answer: RUN!
You continue to go back because you are becoming co-dependent on the high-low serotonin pattern, which is the most toxic relationship pattern of all. Things are NEVER going to change in better, they will only get WORSE! By the time you wake up you’ll have children with him and you’ll never be free again.
Unfortunately, I know from my own experience that no matter the amount of medication or professed love the broken promises, emotional manipulation and defensive rants will repeat on a regular basis. You can change yourself and accept a miserable life but why would you?
You deserve a better life! Love yourself and run!