Maybe she is just confused. I think a lot of people have the wrong idea about mental illness in general and a lot of people seem to think that people who are schizophrenic and bipolar are the "really crazy ones". Perhaps she is just really misinformed and afraid. I would try talking to her. Maybe give her a book about dealing with people with mental illness, something that acknowledges that you realize this will be hard for her too (I know it is hard for you) and that you want her to better understand you so that you don't lose your relationship.

OR it could be really random and maybe she has coincidentally just been really busy lately.

I hope things work out with you two.