Hey Matt, sorry about the current sitch. I had a somewhat lengthy response, then erased it on accident. Jiminy Cricket! I don't like when that happens!
So- shortened version:
Please heed Wonka's advice. The l's get paid the big buck just for this reason. I know this is easer said than done, but you need to emotionally detach from this behavior. It is evident that she is reacting on emotion and will do whatever she can to hurt you when she feels appropriate. It does not mean it will always be like this, but the second she feels threatened, she will go for the jugular.
She knows how to push your buttons. Don't let her. Know that she is hurt and out of control inside. The more she can spew this and hurt you and try to control your sitch, she thinks it will make her feel better. I'm sure it wont last forever, as long as you don't feed the fire.
I am far from an expert on this, but I really feel that if you don't let your emotions drive you, you will come out way better. Even if she never does snap out of it, in the future, you will have the ability to view it as an observer and not a passenger.
Again, I'm sorry Matt. This is really tough. Hang in there. Remember that you are a target because they always want to hurt the ones they love the most. The ones they know they can hurt the most. If it were a stranger she were treating this way, the stranger would be over it, no problem-o. She does not know how else do direct her emotions, so this is control for her. Don't let her control your emotions. Check them out from crazy. Keep your head up.