Why do people make a big deal out of it?

So during school a guy who doesn't like me bothers me and I cant even eat lunch comfortably. It has to do with me saying the n word by accident. I never directed it to someone and today on the bus someone made me read a sentence with the word on it. Again it was an accident and people around me who heard didnt care. My other 2 friends who I dont want to talk to anymore are trying to expose me to the whole school I don't know what to do.