I would like to think my girlfriend isn’t.
I agree with @Haroot that jerks don’t get lasting relationships. In your situation, it seems unfortunate that she regards her family more than you. If I was faced with such a challenge (I too am in an inter-racial relationship, and her parents don’t exactly approve, although they are civil to me) I would be making the choice very clear cut – me or the family.
Although I don’t know a huge amount about the situation, and I don’t really want to, it seems she has made the change because of pressure from family, and has started to forget exactly what you mean to her. Of course you could not pressure her, but maybe you should have reminded her exactly what it means to love – that is, to value someone above yourself.
Culture can be a very difficult thing to deal with. My answer is quite ignorant, as I don’t understand how anyone could allow their family to dictate their romances. The importance of the family unit varies drastically across cultures.
In short, some women are attracted to jerks, but never long term. This may be a form of protection, thinking that a jerk would deal with conflict well and defend them. However I don’t think this is relevant to your most unfortunate situation. Your situation is more a result of a clash of culture and strange priorities.