This is my first post here, and honestly I debated with myself for a long time about even signing up and trying this, so here it goes.

I am a college student in my early 20's. My girlfriend is the same age, and also in school. We have been together (with the exception of several months last year) for almost 3 years. Throughout that time, I have seen symptoms on multiple occasions that I think point to her being bipolar.

First, a little bit of backstory. We broke up near the middle of 2012 when she experienced a pretty crushing low period at the same time I was dealing with clinical depression. In these low periods, I would usually assume that it was something I was doing and freak out accordingly. This time, given that neither of us were mentally stable, it broke our relationship down.

We stayed apart for about 8 months. During that time, her younger brother passed away (I was there for her through that, even though we weren't together) which sent her spiraling downward even further. Then, a month or so later, she was suddenly OK, and has stayed that way for some time. Also during these 8 months, I was put on Welbutrin and saw a therapist for a while, and can honestly say that I have never felt more stable.

My girlfriend and I got back together a couple months ago after realizing that we were still very much in love and were willing to give it another try. Then, about 2 1/2 weeks ago, she began spiraling downward again. Her sex drive vanished, she was tired all the time, and started skipping classes and theater rehersals. It only got worse from there. Today was the first time she had been to any of her classes in almost a week, and has already missed at least 1 exam. She has become generally cold and hateful towards me on the rare occasions that she speaks to me. She has also stopped (or nearly so) talking to her 2 best friends.

I've done some research on my own (and had a long phone conversation with my family's therapist) and really believe that everything points to her being bipolar. Even before her brother's death, her highs (I'm thinking Hypomania) were marked by decreased need for sleep, increased self worth, constant good mood, and a fairly insane sex drive. Her lows, when they came along, have always been the same: isolation, rage and anger towards me (when she talks to me), etc.

This time, it's the worst I've seen. I suspect that she never really dealt with her brother's death, and those feelings are resurfacing now alongside the downward swing of her depression. I am truly at a loss.

I'm trying to stay as objective as possible in this situation, but the truth is that it's really hurting me. I don't know if I'll still have a girlfriend when the sun comes up, or if she'll just cut me out for good in some rash decision. I love her, with everything I am, and I truly believe that she is worth every ounce of what I'm going through and have been through, but what do I do?

Do you all believe that she is bipolar? She's too damn stubborn to seek help, but me and a couple close friends are preparing to try and convince her. Please don't just skip this because it's long and wordy, I just have a lot to say.

I love this girl, she is worth this, but not knowing what to do or if she'll ever come back is killing me. Please help...