I can only 'o' when i have if i think weird stuff?

i'm a girl and i've always been like this since i first began having . i can never 'o' from either or masturbation just by thinking about hot men or hot sex. i always have to fantasize about weird stuff. being groped against my will, thinking about (not with any of my real family just made up situations) being molested by a babysitter. i know this is way to much info but its bothered me for years and i dont know why i'm like it. i was never abused as a kid or anything. i cant even have sex with my boyfriend and have an without make pretending some sordid situation. is this normal? please someone answer! i'm not a sex weirdo i'd never ever hurt anyone in that way or want to be hurted in that way. its just the only way i can 'o'. i literally have never had an 'o' just thru pure pleasure and lust. even when i watch it has to be or stuff. why?!