Look at your expansion tank. Your air pre-charge may be the air in your water this means your bladder has failed and now your pump is deadheading into the tank. This would explain the way it’s running all the time. Try to drain your tank if it does not fully drain you will need to use a bicycle pump to get all of the water out of it before you check the air presure. Most well expansion tanks use a 30 psi pre-charge but you should verify this with your model.
The only way an expansion tank can drain is for air behind the bladder to push it out. If your tank does not drain completely than it does not have enough air in it to displace the water inside.
To drain an expansion tank
First you need to drain the tank as far as it can go by itself. Next using a bicycle tire pump add air to the tank only until the water begins to flow out. Do not over pump the tank or you may ruin the bladder. Keep doing this until you are sure all of the water is out of the tank. Now to obtain the propper air pressure this can only be checked with the tank empty. Most well tanks use 30 PSI empty this pressure is usually 2 pounds less then the rated pressure switch. Now it would be a good time to disinfect the storage tank with some bleach. Use an empty filter sump housing to introduce about a 1/4 cup of bleach into the tank you will need some valves to do this. Now rinse the tank by filling it and draining it sevrall times.
Respectfully David Walling