So there's this boy and I like him, and I'm not sure what's going to happen? Help?

I'm not one to get crushes cause I don't fall for people all that easily. But I have a crush on my friend Tyler, but I call him T. Duff, and there's a small age difference between us, he's a senior and I'm a freshman, and we only see each other about once a day at school in the halls. But we text pretty much all day and all night everyday, and I haven't talked to him since like 4 and its killing me lol, i dont want to start the conversation cuz i dont want to seem desperate or anything. And everybody keeps telling me, Rebekah just come out and say that you like him, but I am so shy but I always flirt with him. And he has got one of the greatest personalities I've ever seen in a guy; funny, sweet, caring and stuff lol. But how do I tell him I like him?, because I never really get to talk to him person? Does the age difference really matter? If I tell him I like him will it ruin our friendship? Anything else I should know or do?