My hunch is that your engine and oil pump are okay.
The oil pressure varies significantly with engine temperature. Mine is pretty much 70 PSI at idle when cold and drops to 35 or so once heated up. I am running 15-40 weight with Liqui Moly Hydraulic Lifter additive.
What oil are you running?
Where is your manual gauge? Below you can see where I get my readings. The sending unit for the oil pressure gauge is relocated near the oil filter.