Unsure about my sexuality, am I bisexual, bi curious, HOCD

Male 20yerars old. I don't know what my sexuality is. From a young age I've noticed girls, I've only ever felt attracted to girls and have only ever had relationships with girls, whenever I've been told a girl likes me or I like a girl, I get butterflies and when I'm with them I get butterflies too and I've only ever had sex with girls and even in this time of questioning, I always get hard when me and my current girlfriend are intimate. Whenever we are intimate I have a burning desire to touch her and just do things with her. I never noticed guys (sexually) at all, one day however, when I was younger I had a same sex experience with a friend, it wasn't something I desired to do, I just did it. I'll admit we did this several times and I always felt like "meh, this is okay but I wish a girl was here" but I never thought for one second I was gay or bi, I'd never even seen actual gay sex at this point till some years after when I got curious one night and watched a gay porn video, I remember thinking "eh, it's just sex but I'd never do that" (actual sex, me and my friend just did oral sex and stuff) I have no desire to be with a man, I never look at a guy and think "I want him". when I saw the two guys in the video do what we did, it had more of a reaction to me. I should say at this point, I've watched all kinds of porn; straight, lesbian, gay, transsexual. I should also say that several times in the past I would turn off a porn video just because there was a man in it. I've also had same sex fantasies but the mans face is never visible, it's more of a penis thing, that's the only thing that is in the fantasy, I've had fantasies of being with people of the opposite sex too and also transsexuals. To be honest, my questioning has purely come around because I've watched many gay porn videos, it's something I'd put on if I were bored of the regular porn I.e lesbian and straight, the same can be said for me watching transsexual porn, but in transsexual porn I don't like watching transexuals have sex with a man. But like I said, after my same sex experimentation, I never questioned myself but I have since I've seen gay porn. Am I bisexual? Bi curious? Bored of porn and seeking more excitement and go to watch something that's considered taboo? Or high sex drive? Or even HOCD? I googled what that is and a lot of how I feel fits into that, such as testing yourself watching straight porn and gay porn to see if I get aroused and I sometimes get aroused by both, sometimes I don't. I do suffer from OCD to a extent but it's not as bad as some peoples OCD. I just don't know what I am.