you probly have a bad oil pump and your metal shavings are your bearings from your crank destroying themselves so stop staurting the thing to check the oil pressure and pull the oil pan pull the pump and make sure the pump turns easily and smoothly and if it doesnt bad pump then next remove a main bearing cap and see how much damage youve caused the bearings and crank and most likely you will need to have the journals of the crank polished and new bearings along with other parts