trans | yay for confusion

I'm a gender-questioning college student. Some weeks, I just don't know if I'm a girl or a boy, as I've strongly felt as both during different times of my life. I'm 18, so you think I'd know who I am by now, but I guess it's too much for me to hope for. It's really stressful sometimes: I don't know how I'm gonna be spending my future, because being a girl would mean having to tell everyone that they haven't really known me this whole time, and I'd have to change schools. But, I also feel male a lot of the time too... so ug! I think it would be so nice just to know what my gender was, ya know?