Not eating??

Has anyone else had a problem eating? I don't think im sick but idk i cant eat the thought or smell of food makes me wanna throw up really bad i havent been able to eat since yesterday and idk why. Idk whats wrong with me. Im not pregnant and theres no chance of me being so what could be happening? Im scared because now i have a massive headache and i know if i take anything it will accept my stomach. Idk if i should go to the dr or what to do. I have been drinking some water but the headache is so intense i cant handle it anymore.