Nobody wants to help this lady?
OK, you've listed a lot of possibilities and eliminated some.
"Pressure dropped rapidly" Foot valve not holding or leak on output side of tank?
"but came on and shut off frequently" Water tank waterlogged.
You eliminated the pump... hopefully.
Pressure switch, replaced with an old one, perhaps it's not working?
PVC pipe burst, sounds like a bad pressure switch, but it's hard to imagine that a jet pump would achive enough pressure to do that.
Call your husband?