Well I think your problem is in the steering gear because you have good pressure from the PS pump to turn left and the pressure doesn't know left from right. I would still make sure all your ball joints are not seized and u-joints if its a 4x4. You should be able to get a reman gear for less than $200, that would probably be the best way to go.
Hi,my son's 1995 psd snapped the pitman arm off at the gear box while sitting in our
garage and all he was doing was turning steering wheel,got a reman from O'RIELLY'S
used to be SHUCK'S for about $150.00,then to make sure we deserved it the adapter
plate on bellhousing broke at the starter this happen in the same garage maybe hexed.