so... being single sucks.... its been about a month and a week.... and just told me he is already moving on and i should too... how do you just convince yourself to not love someone after 5 years? well he also told me yesterday that he was having this girl over at his house... ahhh... its frustrating.... he bought vodka and was home alone... i know because i stopped by for a second to pick up some tickets to his bands show... and she just happened to show up right then... i tried to act like everything was cool and that i was over it, but he was in the other room, and when he relized she was there he yelled at me to get the hell out of his house and pushed me out... she told him to calm down... i dont know.... all i can think of is what might of happened... you know i just cant belive hes already over me... i wish i didnt have to feel this pain. sorry for the ranting i just had to get it off my chest... 
how do you just convince yourself to not love someone after 5 years?
For that you need to focus on the fact that the person you love no longer exists. At some point or over time he vanished into thin air and was replaced by the person he is now. We don't love bodies we love personalities. Things that people do. That's gone now according to what you say (and the fact that you're not together).
I have problems with constantly developing crushes on people that I shouldn't such as married women or people who I know things wouldn't work between us. What works best for me to get ahold of that crush and stomp it into the ground is to focus on our incompatabilities. Belive it or not it's actually pretty easy. Few people are ever perfect for eachother. There's always more incompatabilities than compatabilities. Everyone has problems that annoy someone else. If you can't see them now you'll see them eventually.
I bet if you start focusing on someone else you won't even care about him any more. Of course you'll never forget him, but with enough focus onto someone or something else you will move on.