I think folks older than you who grew up before the civil rights movement made real progress have a reaction to people of a different race...I don't mean just black/white.
So, my experience may not help in any way as you are, I assume, much younger, say under 30 today. Still, I will offer that to notice another person is a different race is not being racist. Even feeling uncomfortable and doubtful that you can communicate is not being a racist. It is only when you do/say something wrong because another person is of a different race that you are acting like a racist, but in fact may not be one you may be reacting independent of the race, say when driving a car and some one "cuts you off"... you get angry with them and if you then drive up along side and see the driver is of a different race does not make your anger, made prior to that knowledge, a racial anger. You were angry because a person, any person, threatened your safety and legal rights as a driver..... just an example. Bottom line, don't overreact to feelings you have that are simply making note of another person's race.
I find more and more that I mentally celebrate when I hear a person of another race say to do something that I admire, it makes me feel closer to them I think than I would if they were of the same race. It is nice to feel you can appreciate someone for "content of their character, not the color of their skin"... an paraphrase of Dr. Martin L. King.
I'm totally sympathetic. I am DEFINITELY NOT a racist, but I hear racist remarks in my head and they are definitely unwelcome.
I grew up in an extremely (though not quite KKK) St. Louis, MO town and heard the most horrible racism all my life. My sister, who I don't talk to, also fed me racism. However, even then, and throughout my life, I have never been racist in my heart.
Voices from the past stay in your head. The trick is to identify them for what they are- not of your conscience but implanted. Whatever is troubling you is something in you but not of you, if that makes sense. I just let such thoughts fly out the way they suddenly came in. I don't think there's much I can do about it. There's a bogeyman in all of us, no matter what our race.