My guy friend told me he liked me, now it's awkward. What should I do?

So on Valentine's Day this year, my best guy friend put a note on my desk in first period when i wasn't looking. When i saw the note it simply said "I really like you. Happy Valentine's Day." I kinda figured it was from him because when i looked back at him he was trying to avoid looking at me and looked really embarrassed. The next day when I asked him if he gave it to me, he looked down and said shyly "maybe...". Since I don't feel the same way about him.. i just said "this is awkward..." and he said "yeah." and we were literally "saved by the bell". So since that day, I haven't spoken more than 10 words to him, and he hasn't spoken to me- even though we see each other in 1st period everyday. I want to go back to being friends with him but I don't know how to... also i don't know if he's sad, or mad at me. I can't tell and I feel really bad. I don't know if he even still likes me. So how do I get our friendship back??