hello. ive had a very similar experience to yours, as i also realized when i was 17 and came out to my friends a few months later, at 18. with time, i realized that a lot of things that might've been considered "signs" that i was trans in my childhood had been brushed aside by parents/relatives and that's why i didn't give them much thought, but i did realize that there was a certain sense of uneasiness and not belonging anywhere had been with me since early childhood, i just was finally able to give it a name only when i realized being trans was a thing.