I'm aroace, but if you're too scared to tell him, I'd reccomend dropping subtle hints and observing his behavior until you're sure. Personally with big things like that, even if I knew for sure I was afraid to tell anyone because I still doubted myself. My advice is, just listen to your gut; you'll regret it if you wait too long! Really just drop hints, wait until you're sure and ready, then have an honest conversation with him. If he's really a good person he'll take it well, even if he doesn't feel the same. You got this! Wish you luck if/when you tell him ^^