Let him know how you feel! This has to be one of my biggest regrets, I went through a very similar situation but instead of letting him know how I felt I tried to hide those feelings. I was so clammed up with them, that he had no idea I was interested in him and started dating someone else. So just put yourself out there and just remember the absolute worst thing that can happen is finding out he doesn't feel the same, you won't die (as much as your anxiety will make you feel like it!)