Hi jidilo and welcome!
Most of us here can relate to living with Jekyll and Hyde partners! You've come to the right place for support.
It's a really positive sign that he is aware of the pain he has caused and is willing to get treatment. Many people with BPD (pwBPD) never get to that point.
We do understand how difficult it is to be in these relationships and to decide whether to stay or leave. How long have you been married?
SaM x