Suggest Treatment For Black Stool, Indigestion And Stomach Issues

Hi im 30yrs of age have a problem with my stomach and acid indigestion every now and then and it drains the life out of me but its at me now about 5 days and my NO 2 is a black tar colour........also getin an excelerated heartbeat the last 24hrs even.by just walkin around the house.......any idea?