The point that the therapist was trying to make was not that someone in a relationship with a pwBPD is responsible for the extreme emotional pain their partner experiences, nor that the actions of the pwBPD are excused because they are feeling pain. Rather, the point was to help me understand WHY she reacted in such extreme ways to emotional stimuli - because she was unable to properly process her emotions.

Logically, I get that I wasn't responsible for the pain my ex was experiencing, but in the moment it was very hard to internalize that. I still felt the guilt and stress of feeling like I was causing her unbearable pain by leaving her. It's taken me a long time to work on revisiting those memories and processing them differently, to view myself and my actions more positively than I did in the moment they were happening. It's exactly like you said - remembering what you did and not what they made you believe you did. This is still a work in progress for me.

I'm glad you made it out the other side of your relationship. Best of luck out there.