SO Confused

Ok, so I'm a guy who is EXTREMELY confused about what my sexuality is. I've scoured this site for some time, but I've yet to find anything that really fits my situation.

I didn't have a girlfriend until I was 18. We were together very briefly and never had sex. When we kissed, I felt no fireworks. But for reasons I cannot really explain, I just kept with it. Maybe it's because we were both about to go off to different colleges and I had never had that level of contact with another person and it was still better than nothing. After I got to college, I had another girlfriend, who I dated for a year. Again, nothing that I would have ever classified as "fireworks", but I did really enjoy being with her. We had sex, and it was good, and I never had trouble getting it up around her unless I was dealing with outside stress (which was fairly frequent).

Then I started to think I was gay. I started fantasizing about what it would be like to kiss a guy, and I got really warm and fuzzy thinking about it, but also very very anxious. I would then picture myself kissing a girl, and all of a sudden, after that first "gay feeling", I didn't feel much satisfaction from the thought, and sometimes it just outright made me uncomfortable to think about even touching a girl platonically.

It's worth noting that in the past I have had many crushes on girls and have gotten physically aroused by them and have masturbated to girls my whole life. However, growing up, there were times (especially around the time of puberty) where I would get small... crushes?... I don't even know if that's what they were... on guys. And there were times where I would think about being with a guy and it would feel kinda good, but that feeling usually went away pretty quickly. There were times I tried experimenting with these thoughts and tried picturing myself with a guy, but currently I cannot remember the results of this. I don't think I really liked it because it didn't become a constant issue.

But now, it's been quite a while (a couple of years in fact) since I felt that really strong gay feeling, and now I can only get that warm and fuzzy feeling when thinking about guys, and girls almost seem to mentally repulse me. But here's the problem: I still get off thinking about girls. Being around girls still makes me hard sometimes. It's just the thought of actually being with them that gets to me. Guys, on the other hand, despite repeated experimentation with porn and pictures, have not gotten me hard. I can't get off thinking about a guy, and if I try to, I end up thinking about a girl. And I'll finish, but then if I try fantasizing further about girls, it goes right back to feeling wrong.

I haven't done anything with a guy yet (I don't really have any options currently) but I really feel like I want to. I think I'd like it, but I'm not sure. As time goes on though, it seems like my attraction to girls gets weaker and weaker while my attraction to guys becomes more constant. But I've yet to have any real crushes on a guy, or really feel attracted to one without going out of my way to try and feel attraction. And when I'm around certain girls, it still seems like I feel some of that old attraction from time to time, but it usually goes away very quickly, replaced by anxiety.

I really think I'm gay, it definitely seems that way... but I just can't get over how I don't feel any sexual arousal. It definitely seems like I get aroused mentally... but I've felt that for girls in the past as well, along with the physical... but now thinking of being with a girl seems like a terrible idea... The problem is that I keep trying to get myself to accept that I'm gay, but it seems like there's this block... and I'm not sure if it's societal fears or if it's something more...

Anyway, sorry for the block of text! I could really use some help with this, so please leave comments if you have advice or have had similar experiences!