which way to go?

Considering the fact that no one reads this it doesn't really matter what I write about. I find myself asking myself the same question day after day on an hourly basis: when is it time to let go and move on? When do you put your foot down and say it is enough? I have let this question hang in my mind way too long, years now. There is always going to be that one person that clings to your mind and wont leave your thoughts no matter how hard you try to hate them. For years I've struggled with following my heart or listening to voice of reason. After being left countlessly, cheated on, lead on, everything by one person,  I still love him. I wasn't perfect either I was scared to be hurt so when he gave his all I pulled away and gave him little attention and spoke to other people. This relationship was so flawed. Now he says he is happy with someone else, but he also gave me glimmers of hope that one day we will try again when I become a more dedicated person. Do I try and become a more sincere person and work on my trust issues with him and hope that we will try again, or do I move on? My voice of reason tells me I need to be strong and push through even if it hurts. The other part of me, the stronger part, tells me to hold on that he will come back and the next time will work because I realize how much I want to have him in my life. The worst part is that I see him practically everyday and I have to try and pretend that he doesn't mean the world to me, it makes me so angry. It makes me angry that someone is making the person I love happy, even if that sounds selfish. I am mad that he left me and I am mad that I didn't try my hardest to keep him happy. Im still presented with the same dilemma; to stay and wait or to go and not look back. Hopefully I will have some sort of epiphany soon and lean in a certain direction. Until then I will remain completely frazzled I guess...