@caitlin5,
Guys can have long hair. Girls can have short hair. Hair doesn't determine sexuality. As Punkey asked, what is it that appeals to you about being a guy? No periods? No bra? An attraction to girls? Wanting to be alone yet safe when you walk in the dark? You can have all of those things and still be female. Is it because you perceive that boys are treated better than girls? That's no illusion; in lots of places, that's still the case. You can be female and work to change that. Or male. There are places where guys aren't treated so well, too.
The reason I'm being discouraging is that the transmen I know, they
knew they were men from a very young age. They went through (and still do) hormonal treatments for years. These treatments are giving one of them terrible acne and oily hair, and the other one is going bald. You know, just like someone born with the XY chromosome combination.
Also, trans means, as you have perceived, a lot of changes. And right now your body is going through puberty changes.
My advice? Go through your changes as you are, at least for now. There is a lot that goes into the hormone therapy for trans. I doubt any doctor would start to treat you now, anyway. So give it a year and see how you feel. See how you feel about what it would mean to come out to your parents, your friends, etc. If you still want to go through with it, then a year of feeling this way would show a lot more of a commitment to an exercise that takes decades.