I used to crave biting human skin
Are you joking? What was so appealing?
I'm an extremely horny person, biting my girlfriend evokes sexual satisfaction for me.
Biting people is a sexual perversion and you need help with this disorder. It is wrong to bite people as it can spread disease and can cause infection.
I'm not doing anything with other people, I just want to suck the blood from my girlfriend. She slams the door, saying she wont let me do it but I can still do it with other girls.
It is still wrong to hurt people for sexual gratification. You need a willing participant otherwise it is assault. Have you tried talking to a therapist about it?