What should I do about a crush on my best friend?

So first, some context: I'm in my first year of college, and came to school unsure of what to expect in the way of friends and relationships. I wasn't even sure of my college's culture toward the LGBT community. Anyway, I got very lucky in finding a group of friends who I've become very close to. One of my friends in particular, let's call him Steven, seemed to gravitate toward me as one of only 3 other males in our group of friends. I was thrilled that he was interested in being friends with me even after finding out that I'm gay. In high school my friends were all girls, and I don't have a lot of experience being friends with a straight guy. Steven and I joked a few times about becoming roommates, because we were miserable with our current ones. Honestly, I didn't think he would ever go for it, and I was only half serious because I wondered if our friendship would even hold up. Last month, we actually did become roommates. He ended up dating a girl in our group of friends (let's say her name is Jamie). I remember feeling really jealous when I saw them start holding hands, but I kind of chalked it up to just feeling lonely. I'm close friends with Jamie as well, although I still get a little irritable when I'm around them together. I tried to force myself to think it was nothing. But all of my other friends treated their relationship very differently than the way I felt about it, so I knew something was off. And somehow, I had developed a crush on Steven. I came to care more about what he thought of me than anybody else. I was depressed for a few days this month like I had never been before, and he was a big part of why. My friendship with him means SO much to me. When I was depressed, he noticed very quickly and tried to talk me through it. He constantly talks about things that he wants to do with me, like starting a podcast together, or writing something with me. He always says we'll be the next Matt Stone and Trey Parker, which I think is cheesy, but he really hopes. I've never had a friend - I think boy or girl - who so sincerely enjoys being my friend. So there's a lot at risk. But he's talked about possibly having to break up with Jamie at the end of the school year, because she's studying abroad over next year's Fall semester (he's told me he isn't even sure they will last that long). I've been considering letting it slip some time after that, which I know is reckless, and nothing good could come after. Is it too unreasonable to think that if he knew, we could still be friends? Could I ever tell him, even in a retrospective way after I no longer think of him this way? I don't, in any way, expect him to act on it. Hopefully one day soon I'll realize that I'm being stupid; maybe I'm boy crazy, never having had a friendship like this before. Thanks for listening to my story, friends.