I'm secretly in love with my friend
Wow, that can get messy.  Do you think he knows that you're crushing on him?
For sure. I think he could tell.
It's ok if you think you're in love with your friend. It's pretty normal actually.
He's single too, I'm just too scared to do anything about it.
You should probably come straight out and tell your friend how you feel. He might feel the same way about you and it could be the start of a new relationship. Just be prepared that he might not share your interest, so try not to do anything that will risk your friendship.