Hi thanks for your question.
One imprtant factor in history you have not mentioned is your age .
The most common cause of epigastric and retrosternal pain is acid peptic disease
with reflux esophagitis
. The second cause could be a heart disease
The most commonly known causes of acid peptic disease are infection by H Pylori bacteria,cigrette smoking,spicy food,drugs like NSAIDS(painkillers) and gall bladder stones.
You need antacids and proton pump blocking drugs like pantoprazole
to control you acidity and reflux.
Consult nearby physician for evualvation of your symptoms.
Hope this answers your question.