I have several similar stories from when I was a similar age–I was a precocious child ahead of the school curriculum in my reading, and had a personal morbid fascination for everything I could learn on my own about WWII–except I never got the awkward conversation with the teacher (or any other observing adult, for that matter). I look back on that period with a full-body cringe for everyone involved, because someone should have seen a fifth-grader checking out Mein Kampf from the library (for example) and had a compassionate educational sit-down with me. Thank goodness the internet didn’t really exist back then.
In hindsight, the key thing was missing in my education (and age-standard level of emotional maturity) at that point was the understanding that these terrible things weren’t in the abstract extremely distant past like most of the history I had been taught, but still directly affected some of my own classmates and friends. I wasn’t able to truly grasp that on my own until several years later.