My bff said im anorexic?

yesterday my bff said im anorexic. shes been my bff forever, and she isnt mad at me. i try to not eat that much cuz i dont want to get fat. i weigh myself like every day and i get really upset if i gain one pound. i really hate the way i look. i weigh 107 pounds and im 5'8" so i know im fat. my friend said she would tell my gramma if i dont tell anyone this week. im really scared cuz then theyll make me eat. what should i do?