Breaking Bonds?

A few months ago, i met someone who i instantly became infatuated with. As time went on, I grew a major liking to them to the point where id be depressed when i dont see him. We've had some fun times in the moments we've been together, but i know there are no reciprocal feelings for me. And now I wont be able to see him again and i wanted to tell him i liked him before we split paths but i missed my chance. And for the past week, ive been depressed over him and i want to know how to completely remove him from my life so i can get over it. But when i tried to it only got worse. Any suggestions?