Dude you should just be thankful you have a gf who you can go home and fuck her brains out to. Your upset alright fine but you shouldn't let something like this tick you off. I'm sure you knew the consequences even before you decided to date interracially and if you really feel you are not comfortable dating or have fears that a black guy or a white guy or any other man for that matter will say something negetive towards you and your gf, why even date interracially to begin with?
If you're the type of dude who loves to flaunt or let the public know you can put your tongue down her throat then that might get some heated attention, but if you two handle yourselves respectfully out in public then I don't understand why you two keep getting flaked on. Another thing, of course whites won't get flak for dating outside of their race. There is so many white people in this world from different countries and nationalities. From Irish to Polish to Scottish to Russian etc, etc. Some can tolerate interracial dating and some can't. Some people is nice some people isn't. You have to learn how to deal with it and move on, this is not rocket science man. You need to stop feeling sorry for yourself like a sad sack wondering why is it ok for the next person and not you who gets shit on, or how come Indians tend to be very close minded when it comes onto dating others? Nothing's wrong with you. All that matters is between you and your gf. That's it.