I screwed up everything! how do i fix it?!?

Its at my high school. Im 13, been nice to everyone. I end up staying with a group of people then leaving them and going to see others in the same recess. Then some people say to stop following them that no one likes me and all that! its stupid because i don't even stay with them much anymore! i only go to see them if i need help for something! i need help cause im loosing all my friends and i dont want to be alone!i don't want people to hate me! i wish i could restart and be invisible!! what do i do? Please help!