Mike is right, removing the oil pressure sender that is in it, and using a mechanical oil pressure sender is the only way to know for sure what your pressure actually is.
Hopefully you just have a bad sending unit, they are easily replaced.
It may be a stuck oil pressure relief valve, if so that should be fixed before the car is driven any more.
When is the last time you changed the oil and oil filter?
When you turn the key to ON, what is the reading on the dash, is it showing 0, or is it sitting at around 60-80 at key ON?
If showing 60-80 or close to that with key ON and engine off, then inspect the sending unit electrical connectors, and replace the sending unit, I'd go with ACDelco 213-1650 for the sending unit.
2006 Pontiac Grand Prix GT with SC
1996 Buick Park Ave NA