I can relate to your feelings. I keep messing up relationships because I don't trust my partner. Then they get fed up and dump me and blame the failure of the experience entirely on me. So I believe it and think it must just be me and my BPD and forget the (sometimes) valid reasons that indicated it wasn't meant to be. I get shouted at for pushing them away, when sopposedly they liked me all along, until I went crazy. I should get help y'know. Apparently I'll meet someone who likes me for me and can deal with my issues... just what you don't want to hear from your ex.
Sarcasm aside, I do try and stay hopeful. Reading these forums I see posts about wonderful partners who understand our behaviour. So far we've just not meant someone strong enough to stick around... but they are out there somewhere