At this point, it's all the usual pieces of advice. It's a proper rinse and repeat situation from us by-standers, and while I realize that it's frustrating being told the most obvious things in the world, there's a reason why it's obvious. These problems of yours are solely in your head, as it is with everyone who goes through something similar. You're going to end up struggling with yourself for a long time, and changing your perspective through any means necessary is the one thing that'll see you through this. It'll happen by itself, given enough time, or you can step out there and try to take the matter into your own hands, work on improving yourself.
Pride is your worst enemy here; don't be afraid of hurting and don't be afraid of showing it.
On a different note, I'd suggest reading a tragic love story. For whatever reason, that always helps me put my feelings on a break-up in perspective. I'd say "Norwegian Wood" by Haruki Murakami.