Most Helpful Guy
The healthy move that's most beneficial? Short answer: Get back to living your life minus whatever part included her.
Long Answer: If you used to workout, then start working out again. If you play xbox with friends, play xbox with friends. If you're part of a sports team, a class, some type of group then go do that. Focus on school/work when you're there.
Cry if you need to cry. Look back at the personal mistakes you made in the relationship and accept that as a lesson for the future (blaming your ex doesn't help you and will only prolong pain. Taking responsibility empowers you by giving you something to change. If you blame your ex, then it's out of your control and you're a victim).
Move on to other people despite what you feel. Talk and flirt with other people, even if you're not trying to take it anywhere. Do it for the fun of it. Just get out there, because other people being attracted to you is one of the best ways to give your self esteem a boost.
If you have hard feelings towards her in any way. Let yourself feel those emotions and really experience it, then let it go. Get it all out or as much as you can. So next time the thoughts come it gets easier and easier.
Most Helpful Girl
Find something that you really enjoy doing, and occupy your mind. Build on a skill that you have, workout even. It will take sometime to be you again but you will get therel