I would cease all contact for the time being, not just for work benefits, but also for your own sanity.. I would imagine her Bipolar may (or may not !) have something to do with it, but i can't really comment as I don't know her.
Break ups are always difficult at the best of times with people displaying odd behaviour, let alone when you thrown mental health in the mix. I've seen it many times in my line of work how peoples reactions to others, be it; friends, family, spouse or otherwise can go from one extreme to the other in minutes..