Ends Plugs 15

My problems started with a spun main bearing. In the process of replacing that, we ended up replacing the crankshaft, piston rings, main bearings, oil pump, water pump, heads, all gaskets, new oil filter, new battery, spark plugs and wires. The issue that we are having is the oil pressure. At first start it runs about 60, after about 15-20mins it will drop to 35, and then after about 30-45 minutes it will drop to 0. We have replaced almost everything and it still won't stay up. We just took down the oil pan and the main bearings can move back and forth. Also there was very thin shavings of metal in the oil pan. Again we did almost replace all these components. The only thing we did not replace was the connecting rods.What did we do wrong and how can we fix it. We have done all this work ourselves.