Popularity in high school?

Hi im 16 yr old guy and a junior in high school. i moved to a new high school last september. im so insecure about going here. im on the bball team and im cool and everything but for some reason i think that people i dont know talk about me. i feel like i have to be friends with alot of people just to be cool. everyday i force my self to wear somethign beacuse i think that everyone is watching what im wearing. I go to the library like everyday because i want to get into a good college. i might go find a grouup of people to hang with but thats sometimes. i dont want people to thiink im a loner even though i know im not. and thats my problem. Care about everyones thoughts . i just want to hurry up and leave high school. is going to the library almost everyday a bad/loner thing to do because you care for your education?