My head tells me let go, and my heart says no way? help!?

ok, so i really like this guy, right, and i keep telling myself to let go becuase he doesn't like me, it just seems like that, but my heart pretty much says, hell no u aient' letting go, u kno u like him!.. it sux cuz i kno i do a lot! i want him so much and everytime he looks at me i really have to remind myself to keep breathing and my heart skips! this one guy i talked to thinks tht the guy i like (lets call him Ryan) is trying to make me jealous. See Ryan is going out w/ this other girl, but whn i asked him 2 sadies he said no cuz he was dating her, but he said if he wasn't he wudda gone w/ me over her. cuz he said no to her. he said i was the best offer he got to and he asked her if i was mad tht he turned me down and she said, no i don't think so and he said, "good cuz i like her and i rele need her to like me bck." i just don't wanna let go. wat do u think?