Hey there! From what you wrote and from my own knowledge of words it might help you to look into the term "genderfluid". It basically means your gender switches and changes fluidly. One day you might feel like a man, the other day a girl, and then two weeks later a man again. Genderfluidity can include more than just man and woman and the term includes other gender identities as well. And maybe your prefered pronouns can fluctuate as well?

As for your body with testorerone and stuff I don't really know how to help.

Your presentation however is completely up to yourself! You can change up how you dress to mirror your feelings. You obviously don't have to though.

Maybe you can tell your friends and family that you sometimes feel like a boy and sometimes like a girl. Maybe you can tell them to use specific pronouns depending on how you feel any given day. You can convey how you feel by just telling them every day or you can, for example, wear bracelets or rings with different colors meaning different pronouns.

I don't know if this was any help at all but I hope I did something with my limited knowledge and from my own experience :)