I am up sh*t creek without a paddle with this guy.?

I have this guy friend who I am completely in love with. (I guess its true that guys and girls can't be friends without one falling for the other). He's managed to break down most of my barriers which is no easy task, believe me. He has my heart. I don't know if I unintentionally gave it to him, or he stole it. (He liked me too at one point). I want to tell him this SO bad, but I know he'd freak out and run out of my life. I know if I had a guy friend say he was in love with me I'd freak out. I die a little more everytine I see him and talk to him. What the hell do I do? I don't think he'd ever be willing to risk jeopardizing the friendship in case it didn't work out.