You have to in my opinion try not to beat yourself up. This is her loss although it feels like yours at the moment. She used a lame excuse in my opinion and a hurtful one. You can't help being Bipolar, there is no off switch. It's just the way things are. Sorry if I sound a bit blunt but from what you have said I agree with the others, there is someone out there for you and someone better. Sending you hugs and I hope you find the support you need and some new friends on PC