My pump is streaming water out of valve from underneath pressure gauge
It sounds like you have lost the air charge on your pressure tank, if an old tank it may need replacing, 
try this it may give you some time , turn the pump off, use a bicycle pump to put air in the pressure tank there is usually a small valve like a car tire or bicycle has sticking out close to the top of the tank, fill to about 35 psi. You may have to open a faucet to get enough air in the tank but if the pump turns on at 40 35-38 psi air in the tank, if it turns on at 30 / 25-28psi in the tank will be needed. 
Now turn your pump and see if it is working normally, if the pump motor turns on and off rapidly more air is needed in the tank so you will need to turn off the pump let more water out and add air, a air compressor can be used if you have one but a bicycle hand pump will work it just takes a while, I have seen old diaphragm tanks last a couple of years longer by just adding air a few times. Hope this helps.