I had a 5.0 sludge motor and every now and then a small piece would make it threw to the sender and block the port, tripping the light.

 

This all sounds too familiar .....there is a reason that you have low oil pressure. Either pump gears are shot or worse. You need to have someone look up from the pan to inspect and remove the front cover to inspect the oil pump gears...does it knock? Slipped sleeve liners are also a problem on these. The hotter to temp the worse it will get....be prepared for dire news but pray for good news ....Sorry dude...temp fix is to add thicker oil, then check the oil pressure with a tester. worse case ...need a new motor best case need new oil pump gears.