I have amazing news for all of you who are or will go through a breakup: It gets easier each time you do it. Not that it's a fun thing to do over and over again - but it's quite a coup when you split from someone and realize you don't feel single. Instead, you just feel like yourself.
The first couple of days were really tough and the encouragement I got here on groupthink was crucial. I am obviously still getting pangs of sadness. I imagine I will for quite a while. But having gone through it several times before, I don't have to convince myself I'll be okay. I know it. I'm finally done panicking about finding a guy in time to have a baby. I finally appreciate the loyalty and wonder of good friends. I can actually picture myself having a (non-close) friendship with the guy I broke up with.
Unsolicited advice: Make a list of all the times you felt slighted or bothered. It will grow and grow, and it's a perfect way to remind yourself that you were putting up with more crap than you realized. I miss him a bit - I missed myself a lot more.