Would you consider this an eating disorder?

Yes. Those are all clic symptoms of anorexia. Please talk to your parents or a counselor/teacher at school. Anorexia can kill you. It strains all of your internal organs and can lead to heart attacks (yes even as a teenager) and other organ failure. You are definitely NOT fat. You are dangerously skinny. Anorexia is a disease that is very hard to kick on your own. Please get some help. There is no shame in ask for help when you need it. You aren't alone. <3