First confirm if the gauge is accurate.
If accurate, how many miles/hours on the ticker?
How frequently was the oil & filter changed, 15,000 mi, 25,000 mi, 50,000 mi? It’s possible the motor is just at the brink of worn out.
If the gauge is accurate, maybe the oil pump could be adjusted?
If all else fails, switch to straight 30w or 40w motor oil, that will help out as you save for an overhaul.