Confused as shit.

For whatever reason it didn't work out. You can't change or reconfigure the past. He probably still likes you, you don't have to completely shut the door but for now keep it closed.

As mentioned before, the only way you're going to be able to get away from your ex is if you cut all contact. Unfriend him on facebook, do not return his calls or messages, etc. Just flat out tell him to leave you alone if that's what it takes. Unfortunately for a lot of guys, and for myself included, we've been burned badly before with the "still hung up on ex" part of getting to know a girl we like, especially if it's a relatively recent break up. It's that indecision that really can hurt someone's feelings. An "I'm not sure" is essentially a "no" in our minds. In the instance of the guy who you rejected whose still sending you lovey-dovey type messages, I think you did the right thing there as well, especially if he already has another gf. You need to find someone who you like and not just keep falling back into the same rut over and over again hoping for things to rekindle with an ex you dated for a long time because it feels safe and comfortable and you had feelings for him at one time.