I completely feel your pain as I'm going through something very similar although I am now almost 2 months down the line.
I'm 28 and my relationship of 4.5 years ended at the beginning of Nov (which was a complete shock to me).
Unfortunately there's no easy way to get through the first few weeks/month it is relentless. You will grieve, cry, shout and it is awful. I also had anxiety attacks as I was left without a home or job (due to a recent relocation). BUT I promise it does start to get easier. One small step at a time.
2 months on and I've laughed, smiled and had fun with friends. I've even chatted to hot guys! Something I never thought would have been possible 6 weeks ago...
Try and speak to a best friend or family, they were my rocks through the early stages and still are now.
I'd also advise getting some space and moving out ASAP to stay with a friend or family. Then cutting contact with your ex unless it's to discuss urgent matters such as finances. Honestly it only prolongs the heartache if you keep in touch. You can't force him to be in a relationship with you, so the best thing is to give each other space and then if does want to reconcile he'll reach out. I know this is easy said than done, I've certainly had a few wobbles.
I promise you will start to feel better with time, you'll even find yourself thinking of all the bad things about him and probably why you weren't that well suited for the long haul. I'm now even excited about meeting someone better in the future and what my life could look like.
I've used the time on my own to go travelling, I went and stayed with a friend who live abroad and managed to pick up a bit of freelance work.
You do not need a man to be happy. Do not let this destroy you. Just take one step at a time 