Listen, reddit is going to tell you to leave him. It's quite possible you should. I'm going to tell you now that 6 years of living context is not parsable in a post here.

He , like you is partially a product of his environment. You have mentioned that he is staying conscious of his authoritative behavior which, means he has empathy ( this is good, it shows potential). The hard part is ( and it will always be hard to hear this) you two are still developing your characters. Some of the best insight I ever received was the person you are at "20 is not the person you will be at 25"

There IS a chance here. You CAN ask him to stop taking his humor to far, saying the N word and insulting gays. That is something you SHOULD do . You can also cut and run, but even if he is the devil himself you will always wonder if you could of helped.

The point im trying to make is that if this relationship is valuable to you in any way you need to do the hard thing and be assertive. Tell him your do's and don'ts and be firm with the consequences. If he gets the point he will shape up, I know plenty of respectable men who were complete assholes when they were younger . If not , he IS a loser and you SHOULD leave him.