Oh dear...

Ok this is it... Im going insane!!
I liked this guy, he got a girlfriend and I tried to forget him... I think I forgot him, but aperntly I didn't... I've started seeing him all the time, like in shcool, on the bus, where people are all the time...He has always been there but now I just see him.. ALL THE TIME! And last night i dreamed about him... And I don't want to like him, I want to move on..
What should I do?