It's been a few days since you posted this. Perhaps, since then, there has been some resolution? I hope so. However, from what you wrote, it sounds to me as though you really do need to get out if haven't already. My personal opinion would be there is nothing you can do to have a positive impact on this situation. And by staying you may simply be continuing to put yourself at risk. I hope you're okay.
Here's a link to an article, from PsychCentral's archives that may be of interest:
https://blogs.psychcentral.com/welln...tner-with-bpd/
I wish you well...