G.B.
I would talk to my mom and tell her all the good the bad and the ugly. Tell her that you want X, and X, and X. That you have a list of goals and that if they are met you will try to reconcile but if they are not that you won't.
One thing though. Bi-polar is hard, it is hard to work through because part of the illness is the desire to feel emotions and the med takes away the ups and downs a lot. A person on them still has feelings but there is not joy, no despair, no extremes but some of the "normal" emotions are effected too. That makes it especially hard on the family of one that has this. It is hard to see them struggle to find the right way.
The only way you are going to understand this illness and be able to talk about it with people who understand it, living with it and living along side it, is to go to a support group for mental illness. Either find one in the newspaper or through the mental health facility he is going to.
He will be able to get stable and live rather normally but it will take time and he will make lots of mistakes. If he was worth something at some time in the past and this illness has changed him then perhaps he is worth fighting for and waiting for the progressions and progress he will eventually make. I would say the separation should not be terminated by divorce for at least 6 months but I would give it a year. Living separately or together, he will have meds that don't work, meds that will make it worse, meds that make him a zombie and some that will wire him up like a spring. It will take a long time and he may never be the same guy, he may be better.