I've had chest pain for a couple of days usually worse after eating. i'm afraid it's a heart attack. it starts in left chest and goes to my back. i've been nauseous and i have a sinus infection?

Dr evaluation : In your young age group a heart attack would be quite unlikely (unless you have an underlying heart problem already) - more likely either a lung problem like pleurisy (which can occur related to sinus/respiratory infection) or a gastrointestinal problem like reflux or gastritis. If fever/dizziness/trouble breathing see Dr ASAP but if not could try acid blocker for few days to see if helps.