If the 30 is the cut off setting, then your switch isn't set right IMO. You should have a 20 psi difference between the high and low settings. So run water until the pump starts and shut off the water. Note the pressure reading the pump comes on at and then the reading it shuts off at. Then shut off the water to the house past the pressure tank. Then drain the tank and adjust the ar pressure to 1-2 psi less than the lower pressure reading OR... if it is less than 30 psi, add air to 29 psi with no water in the tank. Then turn the power on to the pump, you shut it off before draining the tank and adjust the switch to sotp the pump at 50 psi. Run water until the pump comes on and adjust until it comes on at 30 and off at 50.
Then we get into this air in the lines....if as you added air to the tank, you had water going out the drain and the tank still has water in it, you need a new tank because the bladder is broken. If not and the tank was empty, we look for air entering the line from the well. Air could be sucked into a loose fitting, bad pitless oring, split in the drop pipe or a fitting... or, the water in the well is being sucked down to the inlet of the pump. or maybe the pump is cavitating. Or you have methane in the water. All that may not be much help but if you run water and remove the well casing cap and listen intently for water running in the well when the pump is running, since there shouldn't be, you've identified a leak in the drop pipe or pitless and need to pull the pump to fix it.
Quality Water Associates