Hi stguy,
I'd like to welcome to the family. I'm glad that you decided to join us. I can imagine how scary preventing SI would be. Do you have local numbers handy in case of? It helps to read as much as you can about the disorder, the behaviors are confusing but there is a fundamental logic there.
A pwBPD view the world in black and white with no in between, for example good people have bad qualities and bad people have good qualities, they shift back and forth between idealization and devaluation, and it sounds like you've going through the latter at the moment
BPD BEHAVIORS: SplittingPS the lessons are on the right side of the board