You really have to talk to her about
seeing somebody. As was posted above, she doesn't realize that she is the one with the problem.
It sounds like she needs medication and some talk therapy. If she doesn't get on any meds, you are going to have one tough time with her.
The personality disorder is something you might want to read up on and get informed, it does sound like this could be the case.
I hope that things get better for you soon.
Hugs, Karen
I wanted to add, that at the top of the page, there is a section called bipolar resources. There are tips there about dealing with a significant other with bipolar. Please check it out.