You have written 100,000 words of a lesson for yourself, which is that you cannot start by taking harmful stereotypes as givens and then write a harmless book.
Just as protagonists in some ways embody the Big Idea of your story, supporting characters are often avatars of its themes.
When words like "hate" and "agony" come into play, then I do think it's time to consider not doing the thing that makes you feel like that.
You may need to spend more time with your other book and find closure of some kind with it before you embark on a new project. You may need to develop some kind of parting ritual that frees you to move on.