Clueless

Ok, starting to have doubts about my giving my crush a note. I'm half tempted to tell him to just throw the stupid thing away. Why is it everytime i like a guy, I start to freak out like a teenager, outta fear of rejection? I'm not wanting to put him on the spot or lose him as a friend, he means the world to me. I just wish I knew what to do. Any advice is welcome.