Filling the filter is always a good idea if you can, I hate to run an engine
without oil pressure, especially after it's been sitting with out running,
everything is drained back to the pan then.
I wonder if the problem started from a bad oil pump, before you got the
truck? I once had a stuck oil pump blow off valve that caused my turbo
to burn up, there was enough oil pressure to keep the bearings alive, but
the turbo needs at least 40 to 60 PSI to overcome the spinning force of
the shaft to keep lubed.
You could try to pump oil into the oil sending hole, and fill the oil galleys
and the pump before you try to start again, and get a gauge in there
for testing to see whats going on, just T into it and watch when you start
the engine
Good Luck