Hi welcome to the Leaving Board.
It is a very difficult situation when there are those entanglements. I was in a similar situation and found reading about the basic behaviors of BPD, reestablishing my boundaries and learning the staying board communication tools really helpful to bring down the conflict.
Eventually not engaging with the person may be called for depending on where you are at, what you are willing to put up with, etc may be a route to go.
I'd say the most helpful thing was to know what I really wanted too and to go from there. These aren't easy relationships friend, acquaintance, or partner that's for sure.
It's good to hear you are reconnecting with friends. That's important.