I'm sorry if I sounded harsh. I don't want to come off like BPD is some monster, untreatable disorder but OP said she won't see a therapist and her behavior cause him to ask her to leave. Maybe if she was willing and active in a recovery program it would be different, but she's not. Sometimes you need to put yourself first, especially when you're recovering from your own ****.
Living with someone with an untreated (by choice) MI is really difficult, and I just don't want him to mess up all be achieved in order to help someone who doesn't want to be helped.