I was with you until here, but this paragraph seems like a huge leap in logic and frankly based in weird prejudices about girls.The scars are likely from not being accepted, be that pre or post disease. He could have been trying to transition beforehand, only to be bullied by his father, or likely, the girls in his class. I am guessing that he always liked sports growing up, and played with boys, but the girls got jelly of the friendships and bullied him pre transition.