Let's just step back.
You say that that the oil pressure dropped from 0-5psi whilst driving and you pulled over.
I guess that you do not know how long you were driving before you noticed the low oil pressure.
Did the oil warning light come on ?
How much oil is in the engine at present ?
If the oil pressure was that low then I would expect your engine to be rattling its head off.
So what to do is:
From cold dip the oil and make sure it is at the correct level.
Hook up an independent gauge directly to the engine with a known fully working gauge and check the oil pressure.
Hopefully you will find that the oil pressure is good and that you either have a faulty oil pressure gauge or a faulty oil pressure sender unit.