Well, I could've written a fair amount of your post, Clara...
I try to subsume everything and "forget" the problem, but it's always echoing in the background - one thing you left out, I did a lot of things like the girls did. I carried my books across my chest, for instance. I preferred talking, and could talk to the girls pretty well, to roughousing with the boys (a fair number of them seemed to be thugs-in-training, though not necessarily mean-tempered; just aggressively rough. the mean-spirited ones are always a-holes, best solution is beating them down once and for all. but I digress.)
I admired the girl's swimsuits, the smoothness of their body; always embarrassed by my shape, the way my suit would cling to my body and highlight "a certain part"... And at the same time, I was chesty anyway, so it looked like I had boobs, but I hated wearing a shirt in the pool, so I'd go shirtless and have issues...
The girls got to paint their nails, wear jewelry, wear pretty clothes, break the rules, and they didn't hit each other.... And even as a child, I knew girls got better treatment, gentler treatment, just because they were girls.
Lastly, the biggest thing I didn't see you mention...
I've read it elsewhere, though.
I needed to wear a mask all the time, and I needed to think of everything I would say or do, BEFORE saying or doing it. Am I walking like a girl? (Found I used to; my knees would swing around each other, which is part of what creates a woman's sway.) Throwing like a girl? (Don't know, but I've found my entire shoulder girdle is a mess, could be the rotator cuffs, could be deltoids, could be other things too, since I've got my shoulders pinched "up" all the time, and hunched forward all the time...) Am I too gushing as I speak? Am I using too girly words? too many words? (I liked to write and speak, except that it was homework.) Colors, I LIKED bright colors! And lace, too, now I think about it. Satin was discovered a bit later... In my teens.
Coping mechanism, therefore, was to avoid contact with children (my peers), because I was generally smarter and more knowledgeable than they were (on everything), although the girls - who paid attention in school - could actually talk a bit. they didn't LIKE science or history much, but we could still talk. The boys...? Not so much, I was the outcast, and there were a few of us losers (not freaks, not geeks, at that time)... Less athletic, more intelligent, more knowledgeable.
So rather than filter everything, do solo activities.
Models. Model trains, too. TV. Computer games, later. Reading - I had a library of several hundred books by the time I was done, and most had been read. Many several times. Grade school was NOT a happy time. Limited socialization. And most of the girls wanted nothing to do with any of us... (boys, but especially "losers")
And then, better yet, I was given a choice between two all-boys Catholic Prep Schools. (The only good year I had in grade school was 8th grade, in public school. And it STILL had serious issues.)
So, high school not so great, either - but by then I had learned to hide who I was a bit more; and most guys weren't looking for the same "tells." But my parents wanted to make sure I didn't have any "distractions."
No escapes there, though: sports, clubs, theater, etc, all of it was late-night things... No walking to the train station after dark, essentially, and this was before cell phones. So I would've had to make friends with someone who had a car, convince the parents to let me ride with a teenage driver, and then I'd still already had the conversation about how everything was after school, and I was told in no uncertain terms I couldn't do that. I had to come HOME right away.
Then - topping it all off - I had to hide it all from my parents, because they'd make the Westboros look kind. People laugh when I say I'm a good actor.
If they only knew what we are inside!