if the guy your last gf was fucking was white, asian, or another race besides black would you be fine with it?
if the answer is no then your post definately isn't racist. if i started dating a girl seriously who fucked a guy the week before we went out i would be put off too no matter the race. thats why you never talk about your past like that, you will hear stuff that you might not like. i would give this chick a break, seems like she really likes you.. you are letting your past bad experience ruin your future relationships
everyone has a past you are gonna have to learn to live with it as you get older, unless you find a Mormon chick from utah who has never touched a guy before.