Hey, I have experienced this as well, it’s not easy by any stretch of the imagination. The only thing we can change is how we respond to that feeling when someone is being ignorant, since we cannot change them without talking to them and nullifying their expectations of who we are. Meaning, people absolutely can change their beliefs about someone who is different, but it requires being around that person long enough for them to realize that not all people who are ‘x’ behave like ‘y’. This is clearly unrealistic to do with everyone who is being racist towards us, so the only other option is to accept that this person has a drastically different perspective of the world and of humanity. It is usually never a personal thing, they do not know you otherwise the interaction may go differently. The next time you feel the fear, try to observe and accept it. It makes you a much stronger person. Sorry for the long response but I hope this helps a little bit, good luck.