It sounds like the pump end is going bad. If your pump is older than 3 years, it is a better choice to change the hole unit, pump and motor.
When you replace the pump, get one with a control box. If there is a voltage surge or it cycles to often, the capacitor can be replaced. On a two wire, the pump will have to be replaced. There is a big difference between a $20 capacitor and a $700 for a new pump.
That is what I prefer to use here. We have some pretty good surges sometimes, with lighting storms or just a simple power outages.
The two hp sounds like a good choice for what you are doing.