Sorry for the pain you are going through Joe. Its terrible. We don't know anything more than what you said here, but this kind of thing is miserable and no one should have to go through it.
Nothing you mentioned indicates why you think she might have BP. You might have reasons for believing it, but until she is diagnosed by a qualified psych you won't know for sure. BP is a very difficult thing to diagnose, and there are many disorders that have very similiar behaviors.
If she is unwilling to take this step, there is nothing that you can do. She has to be willing to see that her behavior is wrong, be truly contrite, adn try to do something about it.
As terrible as it might seem, this could simply be her deciding to be selfish and destructive and to violate everything that was said before God and friends in the marriage vows.
In my State, as long as you are married you can be held responsible for any debts the spouse runs up. You may want to protect yourself by filing for legal separation or divorce. Take control of your future.
The best thing you can do at this point is to take care of yourself and your child. Move on, because she has. If she sees you living your life and being successful without her, it might wake her up.