The best thing for you to do is to move on because if you keep having feelings for him, your never going to be able to move on. Look for other guys that are interested in you or you look for guys...
For me, I go over the things that made me want to leave the person. Then spend some time being single, have fun, do the things you want to do. Dont think of relationships, focus on the things...
Speaking from experience: Cry it out. Get that over with. Then look around you for something that you can expend your emotional energy on. Something that will be worth the effort or appreciated by...
you take it one day at a time... I am there also my ex went back to his ex before me (huge slap in my face) but my answer is: it is hard but try to one day at a time it will get better... do you two...