Well, I think what you're asking is,
is there hope for the relationship? I think the more appropriate question is,
is there hope for me? And the answer to the latter is an unequivocal yes.
With that said, I've come to believe that the biggest impediment between ourselves and recovery is us. And that's because we give ourselves permission to make choices that get in the way of us fully recovering. I sense you know this, too:
Its really heartbreaking and i would think that im used to it by now and i know its my fault that i put myself through it each time. i always expect a different outcome. i know, the definition of insanity...its really so sad.
Yes, it's sad. But she is what she is. And if you want to keep experiencing the same disappointments over and over, keep doing what you're doing. Which even you know is insane. Or you can do something different: detach. Acknowledge she is what she is, and keep a buffer between you and her such that no matter what she does, you're going to be OK.
What's preventing you from doing this?