Maybe you could try hanging out with different girls? I know what this feels like and the only thing that really helped me was to just push him to the back of my mind and hang out with my friends more. I found that if I had a lot of free time I would think about him so I filled it all up and as time went by my feelings faded for him. It wasnt easy but it was for the better because this guy was a player and I can only see that now