I agree with Echoes......I bucked that idea from a young age......that I would have this for life.
I don't know about a cure, but once you stop searching frantically for an end point, you start living in the moment. I, after 15 years, know this disorder like the back of my hand.......it is like an endearing, petulant and sometimes dangerous friend. I give it a hug, tell it to observe boundaries and let it know who is boss.
I would be loathe now, to even entertain the idea, that it will be completely gone. As much as it has destroyed me, it has also saved my life. It is in me, not of me........I often give it a pat on the head and say, "Now, Now, be good".
I am not phased about the idea of occasionally seeking help through my life, borderline is not the only thing that brings people back to the therapists office.
In stillness........