I hate my teenage years right now

Im 14 and im already ready to be an adult just so i can look different, everyone at my school is so pretty but i can never see myself as pretty, i feel terrible in my body, every time i eat i keep looking at myself in a mirror or a camera and I just stop, i feel so disgusting and ugly in my body, i feel so lazy and useless too, my siblings all play sports but I don’t, all i do is draw and i suck at socializing, i feel so useless and below everyone, i just want to become an adult so i can at least look different, i dont feel good being me, i wish i was a different person, I’ve been exorcising so i can try and loose weight but im scared that if i do ill become more underweight because apparently i am but i just want to feel good, i just want to eat and do things and not having to look at myself in the mirror to see if i feel good yet