Well i think we've pretty much all been in your shoes.
Most of the guys here (not all) will say they are heterosexual and love girls, but we get aroused by a girl with a cock and at first are ashamed and disgusted at our selves, then we cant help coming back for a peek, then we cant stop taking a peek then we stat masturbating thinking about shemales, we try to deign it, then we try to rationalize it, then we come to terms with it, then we accept it, sometimes a few of us will rejoice about it, then it takes over from normal porn and even sometimes our preference for girls.
Its a long slippery slope, welcome to the club, get used to it, there no going back now, your hooked my friend.