Can someone please help me with a guy?

Okay so i am 16, and the guy i like is 19. We met a year ago. We stay up talking till for in the morning sometimes, and i really think i love him. he can always make me laugh and when i see him its like the whole world stops spinning. But, now that hes in college i know hes hooking up with lots of girls and partying. i hardly ever see him now. WHAT SHOULD I DO! no matter what i cant stop thinking aboout him. HELP!?