Thanks for posting your PM here.
It sounds as if you have a leak preventing the pump from building more pressure, but that isn't the only possible cause. It could be something blocking the inlet to the pump etc..
Shut of the water to the house past the pressure tank. Shut off the power to the pump.
Watch the pressure gauge for like 5 minutes and see if the pressure decreases. If it does you have a water leak between the pressure tank and the pump. Probably in the drop pipe in the well.
That only works if you don't have any extra check valves like one before the tank.
If the pressure holds, you need to check the electrical tests of the pump and power cable. Here's a link to learn how to do that and if you can't or don't want to then call a pump guy, driller or only a plumber that is willing and capable of pulling the pump and replacing it.