It sounds as if too much water is going through the geo, as if a flow control is not working. And your pump is doing fine to keep up without the geo, so there's nothing wrong with the pump or the plumbing it is on in the well or underground to the pressure tank.
So check the geo for a busted line, bad flow controller of some kind etc..
BTW, when it comes to pumps, bigger isn't always better and you don't size a pump by hp alone. You first establish how many gpm at whatever pressure you need and then find the horses to do the job of delivering them.