I don't know a lot about BPD but a gal that i talk with somewhat regularly online seems to me like she may suffer from this. I know another person (longer) that admittedly has told me she was diagnosed with it.
Is it not possible that if the other person that is supposed to love them or you truly doesn't put in the time, understanding, effort, patience and compassion to understand the disorder that maybe they cost you the relationship and not you?