I don't think i even know myself?

I'm a 16yr old male. For awhile now i felt as though i'm not sure i know who i am. I guess, maybe, i've hid how i really am, my personality and feelings, from others for so long that i don't even know anymore. When i go to school it's like putting on a mask. I act differently, more quiet and reserved. i have adhd so i guess taking the adderall doesn't help me figure this out lol (adderall mellows out hyper people fyi). I don't feel comfortable in my own skin. I always wish i looked different cuz i don't feel that i'm attractive. i'm unmotivated in school, i do enough to pass. i don't really have alot of interests. I seem to act the way thats expected of me (depending on the situation) knowing that the way im acting isn't who i really am. It's like i unconsciously block people from getting to know who i really am. I have this feeling like there's something missing from me. Like there's a hole in my chest that i want to fill but don't know how. please help! /: