I think my boyfriend is bipolar

I am torn over what to do concerning my 3 year relationship with my boyfriend. We are long distance when I am at home (45 min) and longer distance when I am school (2 hours). ALL of the problems occur when we are not together. He is not been formally diagnosed as bipolar, but he told me the day we met he thought he was. I thought nothing of it of the time but now over the past year its become apparent that he may be right.

The first two years were wonderful. The problems started about eight months ago. I feel like the change occurred overnight, I can pinpoint the exact moment in time where everything changed. He told me he was feeling depressed through a text (which was unusual) and I put it off because I had my own problems to worry about. Not the bet decision. He called me up screaming like I've never heard, he called me every name I can imagine and broke up with me. A few days later he apologized, I wrote it off as a one time incident and moved on. This happened the first day in March.

Through out the months until the end of May, he was extremely agitated with me and everything I said. He yelled at me constantly for putting a word out of place or if what I said could possibly be hinting at something. (For example.. Me asking Do you want to skype? for him= I think that you do not want to skype and you hate talking to me). I got through it and figured things would be better when I got home for the summer.

He has a history of migranes, but before the end of May we never experienced any problems in our relationship with them. He was supposed to come to a cookout, didn't show and blamed it on the migraine. Next day, didn't show. Wouldn't let me come over to take care of him. Finally he said he needed a break. I said that was fine and I'd talk to him in a few days. A few days later, I go on my facebook to find he has made his status single with the status reading DONE! So I called him up upset, and he screamed at me again, saying how I tell him he can't do anything (I was the one who got him to go to school) and I make him crazy. He just screamed all sorts of nonsense things and said we are done for good and broke up with me. A few hours later he texted me he loved me, and a week later we were back together. Throughout the rest of the summer until the last week, things were managable. He only came to my house a few times because he always had a migraine and he took naps 2-3 times a day when we were together.

The last week of summer roles around. I decided to plan out a few fun things to do since I was leaving to go back to school. He blows off all the plans, yells at me and says we need to break. His reasoning was that I stressed him out by planning so many fun things to do I gave him the worst migraine ever. He ignored me until 12 hours before I was to leave, and we met at a gas station to say goodbye. Since then, we have been scraping to get by.

This weekend he was supposed to visit me at school. He did not show. I am at the point where I think I need to say goodbye, but despite all of this I can't let go. I left out all the amazing and wonderful times we have had together, but we had plenty of them even during the past 8 months. I wrote him a letter asking him to seek treatment so that we can be together, but I haven't had the heart to send it yet. I have my own anxiety issues so I am afraid I will never find someone else.

Can anyone else relate? Are migraines a symptom of bipolar disorder or could it be something else? Any feedback is much appreciated.