I've been in love with my best friend for over 2 years. He doesn't feel the same way. What do I do?

I am 21 years old and I'm old enough to understand that I have never felt this way about anyone in my life. I do not want to jeopardize the friendship by telling him because I care too much about our friendship and, ultimately, his happiness over mine. I have tried to get over him but he occupies too many of my thoughts. It's getting to the point where I have dreams that he gets in an accident and the only way I can save him is to give him a kidney. And, of course, I do because I'm madly in love with him. How pathetic is that?! I just wish I knew how to get over this in a healthy way without risking awkwardness in the friendship.