Well hang on a bit here. This does sound proper horrible, and I can't imagine wanting to be in a relationship with somebody with those sexual preferences. Nor could I be in a relationship with somebody that wanted to call me "a derogatory word" during sex, which I'm presuming begins with B or C.
So that would be an issue for me, and if you don't like that kind of sex, then you should not engage with it, and you should consider ending the relationship.
BUT.... BUT.... that's not the question you asked. You asked if it was "abuse".
You say, and I quote:
"I've always had a word that I can use to stop but I haven't used it when I should've because I want to make him happy."
If you told me you had used the word and he didn't stop, then I would say that is rape, and you should run. But you have a pre-agreed "out". When you were "trying to get away", you could have said the safe word, right?
I'm sorry, but to me, if you are engaging in that kind of activity, and have pre-arranged rules and a safe word, the responsibility is on you to use that word when you don't feel comfortable.
If at that point he did not stop, or continued, then I would look at this completely differently. But effectively, you have not let him know that you felt uncomfortable, so how can he be expected to know?
I would hesitate to call this abuse. I think you need to use the word the both of you have agreed. How he reacts will tell you everything you need to know.