If you are taking some cold medications, they could cause you dry mouth.
The stomach pain could be because of 1.Functional Dyspepsia
which is nothing but pain and indigestion
without any ulcer or 2.Gastritis which means erosion of stomach surface or 3.more seriously,Peptic Ulcer
. Did you try the antacids in the drugstore? The doctor might want you to take a 10 day course of Omeprazole