I think i'd look at all the plugs and see if you find any evidence of rust or rusty color ? It sounds like a big leak ! take a compression check while you have the plugs out. that way you can narrow it down to a cylinder or two.
It could be a head gasket .. it could be God forbid a cracked block. If you're pumping that much that fast then check and make sure the intake and the heads are seated right and not cockeyed.
I'll admit thats not a good day, but if its one of the worst days of your life then you're either still young or you've led a very charmed life !!!
