yikes. bipolar or no, this is an abusive relationship and you need out.
abusers are often well-thought-of by friends and family; it's part of how they keep control of whoever they're abusing. most abusers never change, though of course there are always people who manage to rise above their old patterns. if his illness is bringing on this behavior, you can expect that it
will cycle around again someday. anyway, if my illness caused me to be so awful to a loved one, i would want them to do whatever it took to protect themselves from me.
i don't doubt that he has a temper. has he threatened you, or attempted emotional blackmail (i.e. "if you leave me i'll kill myself")? if so, i'd let all my family and friends know that i was about to leave him, that i was worried for my safety, and ask them to be on the lookout. if you're genuinely afraid for your life, talk to the police. look into getting a restraining order, and make sure he can't find you for a few days at least.
more info is at the national domestic violence hotline website:
www.ndvh.org
their emergency phone number is 1-800-799-SAFE (7233)
best of luck, and please take very good care of yourself.