How do I change the pressure settings on my well pump?

My landlord is an idiot. For serious.

There are two houses on the property I live on, and they share a well, but there are two pumps. For some reason, he had us on the wrong pump, so when our neighbors moved out and had the electricity shut off, we were out of water. He came over and switched the pumps.

NOW, our water pressure is really, really weird. The second you turn on the water, the pump starts running. So we get decent pressure that “breathes” down to almost a trickle, then back up to full (meh) pressure, down to a trickle… It’s nearly impossible to take a shower, because you’re intermittently freezing and scalding your flesh in about four second cycles.

How do I fix this without involving the stupid arse landlord?