Let him go... i know it's easier to hear it rather than do it, but you must do it. Life always sends us signals of when to move on; they might be silent signals like a blow of air or huge signals, like meeting someone new. They are always there, but it's your decision if you want to follow them or stay stuck in the thought that one day everything will be what it used to be. People change every single minute, every situation makes us mature a little bit more, it's really hard to go back and try to forget what happened.
Sometimes it's better to just move on by yourself so you can prevent the painful situation of seeing that someone remove you from his life.