Since you showed up to a doctor, I assume that he did an ecg since ruling out heart attack
is of greatest importance. Once it's ruled out, we have to look at other causes.
If you have a burning pain worsened on lying down, drinking coffee or after smoking
, it's most likely to be gastroesophageal reflux(stomach acid coming up the food tube in chest) with or without hiatus hernia( a part of stomach itself moving up the chest).
Medications like Omeprazole
and antacids might provide benefit. But I would advise you to consult with a gastroenterologist and rule out serious conditions like esophageal cancer(cancer in the food tube) with a possible endoscopy