I'm supposedly being racist in year 3 / 2nd grade
That's quite the realization. Do you think you are a racist?
I think my self as a liberal person, but my gf tought me that I'm being racist.
It is good that you think you are not but if your girlfriend thinks you are, you might want to take a look at yourself and how you behave at school. Education is important and people shouldn't be racist since it can affect people who are just trying to learn.
I'm not a racist. I'm a way better person than my girlfriend.
I'm just saying if other people as well think the same as your girlfriend, don't you think there would be something wrong? How about reflecting about what you say to people in school, to make sure you aren't being racist.