Looking for a bit of advice for my situation with this guy.

Sorry for making another "I'm single and so sad, help me" post on this sub, as I know /r/gay is inundated with angsty people like me with no one else to turn to for advice. I just kind of need somewhere to vent a bit and hopefully get some guidance.So, essentially what happened is that about a year ago I met this guy who I decided was really cute and seemed pretty nice so I decided to ask him out when I heard from a mutual friend that he is gay. Unfortunately, he turned me down (and I don't blame him, since for some reason I thought it would be appropriate to ask him out via text. Urk.). I didn't think much of it at the time and brushed it off - I'd been rejected a couple times before and it's not like I had really strong feelings for him anyways.Well, as it turns out, "had" is the operative word in that statement. Since then we've spent a lot of time together and become what I would call pretty good friends; working on assignments together for classes that we've shared, hanging out on the weekends in our limited free time, that kind of thing. He's become one of the best friends I have at university, actually, easily within my top 3. Unfortunately, to my (thus far) endless regret, I've developed scarily intense feelings for him. He kind of makes my stomach fill with butterflies while my heart tries to crawl out of my throat. Being around him and talking to him really make me genuinely happy no matter how I've been feeling prior to seeing him, and when I'm with him I can just be myself and don't feel like I have to pretend to be anything I'm not. I stay up at night thinking about him and when I do anything creative I always find that he's my inspiration in one way or another. I know he's been on a few dates with others in the past year, none of which have ended working out for him (many of which serve to fuel my already flourishing Taylor Swift addiction, with Teardrops on My Guitar and You Belong With Me quickly climbing to the top of my playlist). Though I have never asked him, I have gotten vague impressions from friends that during the first half of last year (towards the end of which I asked him out) he was less interested in romance and dating, but has since warmed up to the prospect.My issue is probably obvious. Even though I'm ridiculously in love with him, I don't think it's appropriate for me to say anything because I already asked him out once. The very last thing I want is to lose him as a friend, and I don't know how he would react if I were to say anything to him or even just ask him out again. To that end I have done my best to pretend that I don't have strong feelings for him. The greatest indulgence I gave myself was writing him a thoughtful and very friendly birthday card, so I don't think he has any good idea of how I feel about him. But the longer I pretend the more it wears on me. I've been hoping I'll get over him or something, but it hasn't really happened yet. I guess what I want to ask is, would it just be crass and desperate-looking to broach the subject of dating with him? I'm not so tactless as to one day just say "Oh ___, you know that I love everything about you and think you're perfect," but I don't know if it's at all appropriate to say /anything/ ever.Anyways, thanks for reading. For me writing things out has always been kind of cathartic (I have a folder full of love letters I've never sent), and knowing that someone out there might sympathize is comforting on its own. Any advice you might have is much appreciated.tldr; I got rejected a long time ago, am now good friends with the guy and have fallen in love with him. What do?