You have a suction leak in the line from the water to the pump or your well is supplying very little water. 1 gpm isn't much for a 1 hp pump. If the pump sounds like gravel inside, it's probably a lift problem or limited water problem. Try testing the well again with your Pitcher Pump. . . they can pump about 4 gpm. If it pumps hard, it means the well isn't giving up much water.