My name is XXXXX XXXXX I will try to help you.
In my opimion the pressure regulator control vavle is stuck in the wide open position. I checked my data resources and I do not have a view of the steering pump, lines and/or steering gear. So I am not sure whether the regualator is built into the pump or placed in the high pressure line. The regulator is simply a valve with a spring on it that by-passes any fluid above a certain pressure to make the steering system controlable.
This is about all I can tell you without being there to diagnose and inspect the vehicle myself.
It does sound like a dangerous condition so I would get it to a reputable shop if you have access to one.
Hope these comments help you.