Fuck, man.
I know that feel bro.
Almost the same situation here just happened to me a couple weeks ago. We weren't long distance, but still. I know exactly how you feel.
story/rant/whine:
Spoiler!
Everything was perfect. From the very beginning, it was pure electricity, and that honeymoon phase just never faded. I've never felt this way about anyone. Waking up with her every morning was a whole new high, and there was never a moment of doubt about anything.
We had plans to do all this and that, travel to here and there, run wild during the summer, etc. I even started moving money around to work out how we could fund our extended vacation around the world.
Then boom.
Out of the blue, she breaks it off.
Needless to say, I was crushed, and felt weaker than I've ever felt. This was just a couple weeks ago, so I'm still kind of in zombie mode right now. Today was the worst it's been so far, for some reason. Probably because I've been in shock since then, and it all just kind of hit me like a ton of bricks today. Took down the picture of us pinned to my bulletin board, gathered all the letters, photos, the rest of her things, and put them all into a box that I don't really know what to do with right now. We're still deciding if it's a good idea that we stay friends. Seeing her with anyone else down the road would absolutely devastate me, so I don't know if friendship is a possible option.
I couldn't sleep, couldn't eat, took days off work, cancelled meetings, skipped workouts, ignored friends, I just stopped caring about everything. But... as hard as it is, try to keep your composure. Believe me, I know first hand exactly how you feel, and it isn't easy. I've never, ever, fallen for anyone as hard as I did for this girl. So it was like I've gone from the happiest I've ever been in my life, straight down to the shittiest I've ever felt.
As tempting as it is to be self-destructive, don't do it. Just, don't. Other than drinking myself silly the next day and getting back on the cigarettes (I know, I know), I've been channeling my emotions into exercise. Plug in your headphones, turn off your brain, and just run as far as you can, as fast as you can. The more frustrated you get, the harder you run. Turn up the volume and turn off the world. And just breathe.
Another thing is, don't be afraid to talk to one or two close friends. It'll seriously make you feel better, not only to barf out your thoughts, but just to feel that sense of human connection with someone you trust.
"It takes a man to hold it in, but it takes an even bigger man to let it out."
Ultimately, both sides need to want the relationship. If she doesn't feel the same, it doesn't matter how bad you want it. You can't force her into something she doesn't want.
Hang in there, man. You'll be alright.
Shoot me a PM if you want. We'll start a lonely hearts club.