first off I dont think you are the weirdo that a few years of repressed feeling have convinced you you are. I have poken to a few women who after a few drinks have adn=mited that forced sex or gang rape by unknown men excites them. Secondly most poeple who are in to BDSM Sadism, S&M etc will i guess be finding yheir feet for the rest of their lives, I know I will be, as this is not a life style you can openly discuss in the bar with your mates as you could a usuall relationship so dont be afraid of you feelings, thoughts or fantansies. And remember they are just that, fantasies, until YOU decide to make them real.
As you said you fantasise about rape, but being raped would be incredibly painful so dont go to the underground with this as a plan. but maybe meet with a man you could get to know and tryst and then experiance it as role play.
Hope this helps as I am a bit of a noobie my self.