my well pump only comes on for 30 seconds and shuts off?

bad pressure switch

Bad pressure switch or possibly you've lost the air charge in the bladder pressure tank either due to a leaking air valve or bladder. This tank maintains water pressure while the pump is off. If you've lost that air pressure, the tank can't maintain water pressure, so your pump runs for a short time, then shuts off. But it's impossible to troubleshoot from here. Unless you are well versed in the operation of your well pump, a knowledgeable tech is required.

The usual cause of that is the pressure tank is waterlogged. There is a precharge of air, either in a bladder or behind a diaphragm in the tank that cushions the water pressure. If water gets into that airspace the pump doesn't have that cushion to build pressure against (water does not compress), Full shutoff pressure is reached almost as soon as the pump starts to move water. Rapid cycling like that is very hard on the pump and pressure switch.

I'd say you had air in the tank. You need to bleed the air out of the tank in order to let the water fill the tank fill the tank.

bladder leak