1997 Chevy Lumina

A few days ago I got in the car to got o work I drove about 8th of mile seen white smoke turned around drove home, husband seen it.I parked the car drove to work inanother vehicle.

water in the oil, upon pulling dipstick also in the oil pan when he drained the oil
but no oil in the waterpump.

husband has already removed the intake/gasket
drained oil, and is trying to remove the head gasket.
we already replaced the water pump about 3 weeks ago. My coolant light goes off and on. Its drinking water, no oil in the water pump or radiator.
we cant find a leak anywhere?
we have spent a good amount of money already,
my husband thinks the blck may be cracked, but he hasnt gotten down that far to check it yet.
if thats not the issue what else can it be.
oil drained looks like babyfood/poop color puke greenish