Oh, my dear...it's AWFUL. Nothing is as terrifying and painful in the world and I just went through it recently as well (I was pleading for advice simply on how to survive it here on EF). It sucks and sucks and sucks some more. I'm a tough girl and it took me MONTHS to get to a point where I felt ok on my own and not constantly fixate on it, not worry about him and his issues, and what went wrong, and what could I have done differently, and stop contacting him. The whole "what if -good memory- never happens again" thing and "there will never be anyone like him" were thoughts I had to actually had to learn to talk back against in my brain. As my very wise mom says, everyone says and MEANS forever more than once.
To this day we're still not entirely out of contact because part of me is still stuck on the idea that we're meant to be together - it repeatedly comes down to the same bottom line though - he's an awesome man but he has to get his own life together before it's fair to me to be a part of it. I'll be the first to admit I still adore him and want him, but it just CAN'T be right now. And every time I get sucked back in, I realize it again, and leave again, and hurt again. And is he better? Yes. Is he there yet? Nope. Until both of those are yesses, I can't give him any more of my heart or my life than I have. I wish I could offer better advice, but I can tell you it DOES get better - a few months ago I was crying all day and not getting out of bed. It might not seem like much but I haven't cried over him in over a week and that's kinda huge for me right now. It DOES and WILL get better. I promise. While I'm not entirely healed or over it, I'm worlds better than a few months back.
Here's what I've tried so far: I read every break up book I could find (Try Don't Call That Man - it's got some great points), went to therapy, upped my anti-anxiety meds, and took up every new hobby I could find to keep my brain occupied (including, but not limited to: oil painting, hand to hand combat classes, re-learning French, going to the gym, playing PS3, preserving fruits, making pickles, advanced origami, jigsaw puzzles, meditation, and trying to learn Navajo). I hung out with friends and coworkers and honestly some acquaintances I don't even like much just to stay out of my house and not be alone. I threw away all of my bedding and re-did my bed so it was MINE again, not 'ours.' I packed away everything he gave me because I feel better not looking at it right now. I make the decision to smile when I want to cry - when I can control it. I try to have faith in the simple fact that life doesn't happen wrong or backwards - you're moving forward onto something/somewhere/so meone, you're learning, and if it's meant to be, it will be. If not, it won't. I got a new tattoo (Mumford and Sons lyrics actually - the chorus to Sigh No More) tattooed on me to mark this transition in my life and to keep me focused on what I KNOW love can be. Some of these things may work for you - some might not.
Keep busy but let yourself feel it. Get ANGRY. Stay physically healthy because it's easy to let your health slip when you feel this way. There's a reason that the majority of movies, songs, and artwork are about love and heartbreak - cause it's that prevalent, everyone goes through it, and when you're in it, it takes over completely. Loss of love may be the world's greatest muse but that doesn't mean I don't f#%*ing hate it!!!
And there will be days that actually feel worse, but you'll get better again. There will be stronger days and weaker days. Til then there's obviously lots of us here that know exactly how indescribably painful and frustrating this is and we're all here for you! The EF community was awesome to me when my heart initially shattered and I don't know what I would've done without them (especially Chili and P'Gell