I don't know what to do! He's like 28 and I'm well a lot younger.?

I don't know what to do anymore because I think I'm in love with him. I swear he hasn't done ANYTHING to me and not shown any interest in me except actaully being really brotherly to me even though he' s just a good friend but....i don't know how to say it but something's there and I don't know what to do. I really do think I'm in love with him and that's really scary cause I'm like half his age. Please help me?