Regular then low pressure from well water
Rule out the pump.

Attach a hose to the drain tap at the base of the pressure tank.  Run the end outside.  Open the tap.  If the water system behaves normally, (Pump runs constantly, or runs and shuts off in a cycle that gives reasonable flow) then your pump is doing what it is supposed to.

Check the line between pressure tank and cold line supply.

Since it affects nearly everything, it sounds like you have an almost closed tap between the pressure tank and where the hot water tank cold supply line branches off.  Most houses have a single tap you can use to turn off the water to the whole house somewhere from.

I say almost closed, because if it drips it will pressurize the line, including any air pockets.  I would expect that you would get between a cup and a quart each time you did this, and it would take minutes to recharge.