Why am i so ...diferent>?

okk, im a 13 year old year girl. Im very shy around mostly people & when im nurves, i twitch like some retard. Boys consider me as...repuslive, ugly, weird or retarded..im NOT retarded and i dont have any problems..too addition, i sometimes were mardi-gras beads around my wrist, mix-match socks and the only one out of all of my friends that never had a boyfriend. can anyone tell me why im so different?