I havent read past the first few posts, but as I have had a girlfriend of 4 years with BPD, and knew her for 4 years before that I can't believe that the OP cares about her in a true sense. They dont choose to be that way, They are often in a lot of pain, guilt, shame, remorse internally, which makes them seek relief through instantly gratifying things which can often be bad, and afterwords she feels worse about herself and the cycle continues. That girl I mentioned, I know her very well, I know her good and bad and what is genuine and what is her taking advantage of things, and 90% of the time she has done things that bothered others it wasnt like she was intending on hurting anyone, but just looking for momentary peace from the intense negative feelings. If your interacting with a girl you know has that, you should either step up and protect her without being taken advantage of, or leave her alone. I dont get bothered by things easily at all but the thought of someone doing that to the girl I know is not cool theres nothing manlike about doing that, to say the very least. Going out of your way with intention of bringing harm to another person is already bad, but doing it to someone whose handicap is largely due to feeling very intense negative emotions they cant always identify or manage is just cruel. No matter what she did to you, I dont have to go into detail about how getting revenge will never do anything genuinely good for anyone because I know you already know.
Im not trying to start a fight with this post so hopefully im not excommunicated 5 posts into my stay here lol