And this is certainly the same premise of why your boyfriend broke up with you.
If he broke up with you then chances are he probably perceived you as not being happy in the relationship.
You might think that's a crock, you're really happy, but maybe you only showed you were happy in other areas of your life? Did you only show happiness at work, or with your friends? Did you save up all your grumbles about your day when he walked in the door from work? Cause after all he's a great sounding board.
You might say to me, NO!!! I showed him I appreciated him, I was always bending over backwards, but ask yourself, deep down, were you happy? Or were you keeping score? Did you have an agenda? Did you think that if you showed appreciation too much then he would take you for granted? Did you think there's no reason to show him you're happy when you're the one doing 90% of the housework, and you're working? Were you controlling? See when he perceives you as not being happy then that's a huge burden to him, he feels it falls on his shoulders to make you happy.
Wait!! You never expected him to have to make you happy.
Maybe you didn't but your attitude still affected him.
I bet when you first got together you put all your problems aside and just had some fun.
You showed your enjoyment.
You were a lot more light-hearted.
If you're fun to be with and enjoying your life then that's enough for any guy to stick around.
OK sure, maybe he left because he's an addict or running from the law or has serious mental issues, but failing that it doesn't take much to keep a guy happy.
I'm not saying that you have to dismiss all the problems you have, maybe his behaviour is part of the reason you're unhappy.
If he cheated on you and found someone else, chances are she's happier than you were.
I'm not excusing his behaviour but explaining it.
I'm saying if you want to know why he broke up with you, 9 times out of 10 it's because he feels he can't make you happy anymore so why bother trying.
If he really is one of the good guys then perhaps you can start working on making yourself happy and when you feel better about that part of yourself then it might be time to contact him.