I am sorry this happened to you. Whether this was an official relationship or not you felt an emotional connection to him and he hurt your heart.
I would suggest you exercise, watch some favorite movies, hang out w/ your girlfriends or do any activity that energizes you. But, don't be surprised if you find you mind wondering back to this guy. That is completely normal. Don't try to figure out what you could have done differently because there is nothing you could have done to change the outcome. In reality time is the best healer and everyone's amount of time needed to move on will be different. I promise you though that you will get over this guy. Best of luck to you.