he said during that talk that he sensed me pulling away so he made the move to end it 1st. As someone who has done ALOT of reading on BPD to navigate him this rang so text book. As I know the greatest fear he has is abandonment and if I leave first it confirms that he was never of value and confirms his empty vessel feeling. However if he pulls the plug first then he can "split" and convince himself I was never of value and discard me easily avoiding the abandonment he thought I was going to perpetrate. I need him to allow me to put boundaries in place as I have my own scars from a DV partner and all his betrayals and need to feel emotionally safe in this relationship. I just wish he could be empathetic in understanding it from my pt of view

I felt this at my core. You're absolutely correct that him pre-emptively ending the relationship to avoid the possibility that
you might abandon
him is pretty textbook BPD...even if you haven't been actively expressing any desire to leave the relationship. His emotional experience & insecurity ring louder than your words of affirmation that you love him.
my 27 y/o GF with BPD frequently pushes me away/threatens the relationship when she's afraid or overwhelmed by the idea that I might be thinking about leaving the relationship. I think for a long time she's known that something was plaguing her, but it wasn't until a few months ago that she was officially diagnosed. But even with a diagnosis and at least some level of commitment to wanting to understanding her BPD, that doesn't mean that she's yet capable of seeing how obviously "textbook BPD" her behavior is in various moments.
The intense fear of abandonment drives the ship, and it overrides the efforts that you make to try to help the pwBPD feel loved & cared for & important. So yes - for a pwBPD, the easiest thing to do is exactly what you described - do to the other person what you're afraid they might do to you before they have a chance to, and then you can paint them black after you've discarded them to justify the act. I'm in the process of being discarded right now...it's brutal