I am confused..

Hello! I am 17 years old (male), and for several years have been struggling with my sexuality. I have been reading a lot of posts about people being confused with their sexuality, and felt like I should throw my story into the mix and see if anyone has an idea what the hell is going on with me. I remember being about 5, and having dreams about naked guys (imagine a naked Barbie that's like a piece of plastic with no distinct genitals or whatever, it was basically that). Over the years I went through a lot of phases that might seem stereotypically gay (ex: I would put a dishtowel on my head and pretend I was Avril Lavigne, obsessed with Lady Gaga). While all of this was going on, I still definitely had romantic crushes on girls, without a doubt. I thought they were hot/pretty, but when the thought of sex came to mind, it was only guys that really occurred to me. Now, I am almost 100% only sexually aroused by men. I can look at a girl and think she is hot, but I've never gotten aroused from looking/thinking about a girl. The thing is, I've never had a crush on a guy like I have with a girl. I've definitely had crushes and have wanted to date girls, but sexually, I don't feel anything beyond that. Dating a guy has just never seemed like something I'd want to do- and I don't think it's just a "society" thing, I really just don't want to. It's more of just a physical thing. For a while in middle school, everyone thought that I was gay and it was a big thing, but now in high school--I haven't heard anyone mention in (even with rumors or anything) in a couple years. I would classify myself as an average guy. I'm not flamboyant (I am not trying to be stereotypical, I'm just basing this off of what I've seen), and just sort of chill. One thing I've noticed is that no matter how hard I try, I physically cannot talk about gay politics with people-- I stutter and get flustered and it's pretty embarrassing. Or when a guy playfully kisses my neck (yeah, that happened the other day), I just sort of froze. No arousal though, it just felt like my brain short-circuited. Any thoughts? I'm just really confused, and this is always on my mind. Thank you!