I have had friendships fail. I have had romantic relationships fail. Honestly I find that my relationships work when I have been diligently working on myself and my BPD. I have been with my fiancé for 4.5 years and we are still going strong through two hospitalizations, couples counseling, and many late night calls to crisis. You just have to be prepared to have a rocky road. I think this is true of any relationship but BPD makes things tricky. Don't give up though. You will find the one for you in time.