Relationships that start out as friendships have a much better chance of being healthy AND surviving.

My bipolar doesn't bug my bf at all probably because he knew it was part of the package before we started dating.

There are quite a number of folks on the bp forum who are married or in longterm relationships, so I wouldn't say you're doomed because of a diagnosis.

If I had to guess, I would say you're seeking out the wrong type of guy.