I (MtF) also on a similar boat, only having male sonas until I actually realize I’d rather be a girl. Having assigned-gender fursona did help with dysphoria, though, as he helped me project myself into a character that’s my distinctly not me.

I wasn’t myself, I was my male fursona. That sort of dissociation helped me cope with dysphoria up until I realized myself as transgender. So, yeah, I had a fursona that was my birth sex before I discovered myself.

Funnily enough, when I designed my first fursona, I made his color white and pink because I wanted to subtly rebel gender roles at the time. I didn’t think of it much aside from messing with gender roles, but looking back, that could’ve been a sign.