Is it normal that i fantasize about.. (warning: explicit)

Something Ive been trying to figure out for a very very long time. My sexuality. I have had sex with a man. There was a time when I was so very uncertain that I allowed myself to have (protected) sex with a man. From that, although I found the experience enjoyable, I decided that I personally just could not find myself loving a man. Or being attracted to one. Hair on a mans face, and the idea of kissing it, has always been a big turn off for me. But since then, I still fantasize. I still masturbate over the idea of sex with a man, giving a man oral, receiving from a man. Some of the best orgasms I've had have been while I've been penetrating myself with something long and smooth. Sorry for the detail but it just continues to beg the question: What am I? I love my girlfriend. I do. I want the world for her. I love her smile, her attitude, the way she laughs, the way she talks and the way she acts tough but is incredibly self conscious to a level completely unnecessary. I love having sex with her, I am incredibly turned on by women, by breasts, by a beautiful face, and I can't find myself looking at *ANY* man and wanting a relationship, or even finding them attractive. I see them as objects sexually... until I think of what I could do with what is in their pants. It arouses me to no end.