I learned to manage my BPD through therapy and diet. I quit eating white Sugar and white flour, and my splitting/swings/cutting/rages stabilized 50%. I also started doing a lot of NLP (Neurolinguistic Programming) process work, and that took it to 95%.
I actually feel like a completely different person was inhabiting my body. I hate to be reminded of things that I did or said just 2 years ago, because it feels like it happened to someone else and has nothing to do with ME.