I'm so sorry to hear about your break up.
I totally know what you're going through. About four years ago I was with a guy that I thought within the first five minutes of meeting, this was the guy I wanted to spend the rest of my life with. Fast forward six months later and a very on again off again relationship, I realized I was way more into him than he would ever be in me.
The relationship ended, and it was like someone took a knife to my heart and cut it out. I cried for days. I thought I would never love someone as much or as deeply as that again.
I'll be honest, it took years to get over him. The best way I found to deal with it was to avoid him completely. I went out of my way not to go to places I knew he liked. I didn't want to talk to friends about him. I also didn't check up on him online. It's tempting I know, but every time you check his facebook page, you're just opening up a new wound.
I'm not going to tell you some magical cure for the pain. It's just something you have to go through. But try to avoid him as much as possible. Don't get trapped into the whole lets be friends game. That will always set you up to think there's a chance it could work out again, and it won't.
After a while time will pass, focus on yourself, your career, etc. Hang out with your friends, but don't talk about him.
Believe me, the pain gets better. Also, I've since been in relationships where I've found men that I've cared even more deeply about. So don't let yourself believe you'll never find someone else you'll love as much as this last guy. You will.
Hope that helps.
Gaylynx