Do I listen to my mind or my heart?

there's this guy, and he's absolutely perfect. I mean perfect, for me. When he's in a room, I can feel him, he "lights it up". The more I find out about him, the more things seem to fall into place. I love him, I know I do, but I'm not so sure he feels the same. Being around him makes me so happy now, but I have this insane urge to tell him, because I know if i don't, nothing will happen with him. How can I not, i mean one day of I'm dating someone I'll think about how this guy is perfect and no one else is. At the same time, I'm already happy, and I would feel horrible if I was rejected and I would feel sooo embarassed. What do I do!!??