I honestly think it was exposure to female kpop groups from a young age, as well as other hyperfemme queer positive western pop music, as well as anime. due to my autism I tend to hyperfocus on things and enjoy repeated stylized gestures, I also tend to latch on to rigid perscribed roles as a social crutch.
I also think social media played a role, since women are able to constantly post filtered airbrushed and staged photos emphasizing their most beautiful and sensual feminine qualities. There's just nothing in male culture that compares. Overtime my male identity was overwritten. Deciding to finally give in and have sex with a man was just the beginning of the end, as I knew I only wanted to have heterosexual sex + marriage and at that point the only way to get it was by taking on the female role. I never had male friends growing up so my first close exposure to men was in a sexual and romantic context and it's hard to keep feeling masculine after that.