I've been having chest pain right in the middle of my chest since last thursday evening after eating ice cream-which i never eat. i have a history of gastroesophageal reflux disease but it usually doesn't last this long nor does a heart attack right?

Is it true that you never ate ice cream before last Thursday? At your age, substernal pain as you described is less likely an cardiac pain in origin, especially it has been persistent. Cardiac pain is usually triggered with activity and it associates with shortness of breath and sweating. GERD is more likely and you can do therapeutic diagnosis with Omeprazole / Prilosec / Nexium /Prevacid, OTC.