Idiot Oil Light

Put a manual gauge on it and drive it. This will tell you for sure if it's a problem. If the manual gauge does the same thing then you know the light isn't lying. Plus how many miles on the engine? It could be that the bearings are that worn and the idle is dropping to low. But the manual gauge will tell you the real oil pressure you have. Maybe a crack in the pickup tube. Is the bottom of the oil pan look dented or smashed?