"You are not a tomboy. You are a Black girl" is going to stick in my head for a long time. there is no room for gender variance when everybody sees you as innately less worthy of gender. ambiguity is a comfort, but a luxury; a constant game of self-adjustment, predicting how you're read and responding in advance.
i had a lot of similar feelings about yaoi and yuri when i was a lesbian - particularly, confused guilt for my attraction to fictional boys, in spite of my (then) lack of attraction to real men. the fear that your gender is just too inconvenient to understand, or that you're "lying" by wanting something different than the way strangers perceive you... i really feel it.