Sorry, man - that's not a great place to be. It's been a while since I've been there, and I don't know enough about your situation to make any sort of informed, specific suggestions...
But in general, you can't really do anything about the other person, their actions, or their feelings. You only have some measure of control over your own self, your actions, and your feelings, so focus on those and take responsibility for the stuff that you did (or didn't do), and learn from it. Whether things get better with the other person or not, at least you'll have learned from it (as painful as that process can be).
Best of luck.