At some point IMF , you/ I/ we are forced to decide what and whom we are truly responsible for. That which will fundamentally destroy the will to live along with one's sanity ?or one's right to continue with dignity and respect.
That describes the caretaker role in me.
Care taking of others... .
All at the expense of the caretaker themselves... .
Me.
It's ok to choose yourself. In fact, when dealing with BPD, it's really the only sane choice, or leaving them. Either way, you stay or go, you will need to choose "me". It cannot ever hope to survive any other way. Choosing " me" in a PD r./s leaves one pretty much alone and lonely though. So suggest to Choose "me" and leave her permanently out of your life.
Love is a beautiful thing, with a PD , it is not about Love, it is Need. It's not the same. It's weak and has no foundation nor depth and never will. It's what they are. Voids. It gets worse over time as well.
Save yourself.