I am not really sure how to reclaim that confidence and to have hope that love is actually possible.
Just be yourself; the same loving and caring person that you showed to your partner. Sadly, his condition prevented him from seeing and appreciating what he had but that was always his problem, never yours. You will meet someone who will return all you give them so stay positive. You had a life before you met your ex and you will have one again. The world and all its possibilities are still there. I find that good things, like meeting someone new, happen when I least expect them so be ready!
I too had hopes that one day my ex would just suddenly 'get it' and see how destructive her behaviour was and we'd be a happy and committed couple from then on but of course this just doesn't happen with BPD as the condition is ingrained so deeply in them.
I remember having - or trying to have - long talks with her but she would usually just stare into the distance, appearing totally disconnected and barely saying a word. The total lack of communication is one of the most frustrating things to cope with, as I'm sure you'll know.
There comes a time when even the most caring and patient of us has to now put ourselves first.
Best wishes