Can someone help please life is messed up?

My life is a mess. I live in a flat and I don't like it because it's far from my school. I worry about everything and exams and I'm shy so I worry about fitting in and friendships. I have a group of friends at school but there's always someone who you don't like. I worry about those people in case they say something to me and I get worried and upset. Next year I finish secondary school and I can't wait but I think time is going slow... :( Also, I'm quite plump and I really want to lose weight and grow my hair but I can't seem to lose weight even if I try and I feel shy when going out and I feel I don't have real friends like I can count on them to go out and I don't know I'm 16 and confused about everything just want to be happy like before when I was younger and I can't wait to finish school can someone give me advice thank you x