My advice is to let it go. I know it sucks, but honestly if it didn't work out for you two to get together back then, it probably isn't going to work out now.
I haven't been in the exact same situation as you, but I've been in similar ones. My experience is that it really wasn't worth the heartache to keep hoping and trying to make something happen and I really wish I had just walked away earlier.
I know I'll find someone with which a relationship will happen organically, naturally, easily. No games, no drama, just two real people who really want to be together. You'll find someone too. Not this girl, from the sound of it.