Boy problems... Need Advice....:)?

So there is this boy i really like..lets call him Mike... Mike and i have known each other for 8 years but we never talked to each other until about 3-4 years ago... i've liked him since the 5th grade (we are in eighth now) and last year he admited to my friends he liked me.... I was really excited about this.... but now this year he doesn't talk to me, or even say hi to me anymore.... its sort of depressing.... my best friend is saying "get over him" but i think in my head he's nice, sweet, smart, and is a jock... well not really i plays football really well but he's like a nerd jock...Ha-ha... well anyways i was wondering if you can help me by telling me what i can do for Mike to remember i like him and talk to him alot again... by the way i'm not very outgoing and we don't have any classes together but we pass each other in between classes a few times through out the day... please help me i would be soooogratefull... thanks for reading all this!!! :)