Yes, judging by what you write, you are. I think you know it, but it's a big step in any person's life, so I can understand you putting so much thought into it.
Look at it like this; i'm heterosexual and the thought of being with another guy is very strange, and doesn't make me feel good (i think disgusting is too strong a word). It seems like you have the same feeling about women. We were both born like this, and it's our natural instinct, so if your natural instinct is how you described, then yes, I would say you are homosexual.
Hope you can think about it and accept it, you'll be more happy than if you actively deny it.
Someone tell me if i'm wrong, i'm only 19 so I don't have a ton of experience.
But yeah, what the girl above me said is correct.