I am suffering from acidity... what can be the immediate cure?

Antacids: A sense of gastric acidity, with pain in the upper abdomen, and a sour taste in the mouth, can be quickly alleviated with over the counter antacids that contain either calcium carbonate or aluminum and magnesium hydroxides. If symptoms are frequent, consult your doctor, as you may need stronger medications. Many strong medications are available over the counter as well.

Immediate: Immediate relief with antacids such as Tums (calcium carbonate) or mylanta. I you get heartburn more than once or twice per week you should get checked out.