I feel so fat :(

Okay so I’m 15 and I am unbelievably insecure about myself and I just feel like everyone around me is prettier and skinnier than me. I’m 5’3 and weigh 8 nearly 9 stone ( idk what that is in pounds) and I really need to know if this is healthy or overweight cause I’m worried that if I keep thinking like this I might develop an eating disorder and I’ve seen and read all the stories and it scares the shit out of me. But my appearance just keeps giving me anxiety and I don’t feel good enough. Any advice?