Im Confused can you help me?

Let me start by introducing myself I am Jaci. I have a question, well questions actually. I am of course confused. When i was little i used to think i was a boy. I took my shirt off. I acted as if i was a boy(except when i peed). Anyways, lately i have been acting the same. I am Always being shirt less and i like girls. I am just a little confused, there's more then whats been said right now. Like how i want to be flat chested. I keep asking myself what if i was a guy. Okay what i'm trying to ask is could i possibly be a boy in my mind and a girl physically? I never understood why i like dressing as if i was a guy and i love it when i get mistaken for one. Don't tell me its a phase i thought about it for a year and the confusion keeps getting at me. I am honestly 13 years old, almost 14. I like girls, i like dressing like a guy and binding my breasts. I am just scared that i could be a Transgender.I can't talk to my therapist about this i'm too unconformable. And i don't wanna speak to my mom about this either. I just don't want to make a mistake and screw up my life. I really feel that i am a guy on the inside. I like cute things but i like them on girls, i am also very manly , much like a boy. I can't trust my friends i am scared they wont understand me. And make fun of me. So i am willing to ask strangers who don't have any idea of who i am. Please, Please tell me why am i so confused? Who am i? Because honestly i don't have a clue.