ive seen something similar on tv. i dont blame your girlfriend for not liking it... i think a lot of people would be freaked out by the blood thing. so to answer your question, no you are not a freak but it certainly isnt normal to crave blood.ive heard that craving raw meat can mean you need iron or that you have aggression built up.

im not sure where you could get a source of blood thats legal....
or moral....
and above all else,
i think you should find something else to be obsessed with.