Advice on how to deal with my crush on my guy friend?

Please don't judge me. I am quite frankly on the brink of insanity right now. So there's this guy named Aj. We met freshman year while I had a boyfriend, but I broke it off twice for Aj and consequently went back to my old boyfriend twice. I'm a terrible person, I know I'm surprised the kid even speaks to me. But sopre year we had a few cles together, common friends, so we chilled a lot but we weren't that close. But the summer of sopre year we got insanely close, like we would talk 24/7 about everything. He told me how beautiful I was, we talked about what we wanted to do with our lives, the things we wanted to do, how hypocrital relationships were (remember this it's important). But he had a girlfriend that summer, but things still felt more than friend-like and they just escalated to me making out with him twice while he was still dating her. But then after, rather than it just being making-out, he would hold my hand and we stayed up all night together and got breakfast in the morning. Then, sure as you know it he breaks up with his girlfriend. He tells me he did it because he didn't want a girlfriend label, which may be true or it may be because we both talked about how much we hated relationships and it'd be hypocritical for us to get into one. So we're in this place of friends/more than friends and we hang out and make out a lot. One night my other friend (who also told me he was in love with me awhile ago, that Aj was just using me, but it may be just because he still liked me because he would be the type of person to do that) so I finallly confronted Aj about his feelings (we're both shy about those things) and we both admitted we liked each other and if it worked out we should date down the road. That was like July-ish. Things continue like this, and then one night we were at a party and both got intoxicated and one thing led to another and we had . While not in a relationship I know, I make awful choices. My friend told me I blew any chance I had with him by giving it up to him so easily, which I so did not intend to happen. Now it's August and we're back in school and the first time I saw him he came up and gave me a huge hug, and wanted me to sit with him and our friends at lunch. But it's with "all the guys" so it's not like things can be romantic, it'd be awkward with everyone there and essientially it's making me seem like "one of the guys" to him all over again, I believe. It may very well be my fault, for having with him, and I get really shy and should make more effort to be more flirty but I just really wouldnt want to lose our friendship so sometimes i'm brave and flirt but I really don't think I'm flirty enough to get the message across, mainly because we're always around our group of friends and it'd be awkward with them there. But signals: he hinted at homecoming, and was going to sneak out last weekend (he's grounded, so it's hard for us to see each other without everyone there and we cant text) but it might very well have been to see everyone, not just me. And he brought me cds he thought i'd like. And whenever I want to go buy lunch in the lunch line or something he jumps up to go with me every time. But at other times, it's more friend like, we'll p each other in the hall and not say anything (partly my fault I get nervous and avoid his gaze, stupid i know). And my other friend, the one who told me he was in love with me once, told me that Aj has nothing more than feelings of friendship towards me, which is probably whats making me nervous to flirt with him. But regardless, I'm going insane, please tell me honestly what you think, and what I should do.