it's a common misconception that a lack of oil pressure is due to a bad oil pump
The question people always ask is "why isn't the pump making pressure?"
instead of understanding that pressure is a symptom (good or bad) to
resistance against the flow of the fluid being pumped.
the question that people should be asking is not why they have a "pressure problem", but where is the pressure/flow going...
In your case it's fairly obvious that the oil isn't going where it's supposed
to, but wherever it's going it's a very bad sign.
For today, just today, whatever your name really is you are honorarily "Jim"
Just so I can say: "It's dead Jim!"
Sorry, I wish I had better things to tell you, but that engine is gotta come out
and frankly it's probably not worth putting back together if you do take it apart to determine what went wrong inside.
AD