“BPD abuse” is not a thing.” Your girlfriend was an abuser. Full stop.
The idea that someone’s mental health issues has any involvement in the form of abuse they perpetrate is twisted and unhealthy and unhelpful.
Doubly true when that person is themselves a survivor, as most of us are.
It leaves no room for the reality that most of us recover. Many people recover without diagnosis. Most people find diagnosis a useless exercise.
Your experience sucks. But I can hear even from here how much it’s still impacting you. Both how much identity you have invested in being victimized by a particular type of person, defined in turn by how they were victimized; and how much that one experience allows you to stand in judgment of others’ pain and their humanness and shame now.
I’ve been there. It’s not a healthy place.
Best of luck getting out.