I know that you believe you’re not writing fiction. You also probably believe that you have an “objective” view and that your writing makes sense. In answer to your question, NO, black people cannot be racist. They can hate white people, generally for good reason, but because they cannot influence every aspect of white life the way white racism influences every aspect of black white, they (we) are not racist.
It’s moot whether or not I would enjoy your sex story. I doubt I’ll be reading anything more from you.