Is my fiance suffering from BP?

I have been with her for almost 2 years now. The first time I noticed her behavior was only a few weeks after we met. She suddenly started trying to control everything, acting like a control freak, and got angry, very angry if she didn't get her way.

She then started to see a counselor (psychologist), and told me she has anger issues, mainly caused by her childhood. Her mother was a very angry person herself.

Ultimately, I got invited to go to her sessions, but she stopped seeing the counselor after a few weeks. He said things she didn't want to hear, and it made her angry.

During her anger crisis, which last between 2 days and 2 weeks, she becomes distant, tells me she needs space, she watches tv all day long and eat comfort food all the time, and wants to stay alone. If I try to approach her, she push me away violently. Most of time, it gets so bad that she thinks about leaving me, blaming me for her anger and for everything. I sleep alone on the couch during these times.

But then she becomes normal, loving, caring, until the next episode.

My life is not bearable since she seems to have more and more episodes, and the intensity just raise every time.

I'm thinking about leaving her. Unless she realize she has a problem, and be willing to work on it.

I believe she might suffer from bp, but she doesn't show the intense high. Just go from normal to very depressed/angry...

Any clues what this might be?