Need some help badly with my '02 F350 w/ a 7.3. Here are the symptoms:

Wife was driving the truck about a week ago. Was low on fuel (below 1/4 tank) and she stoppped and got fuel (100% sure it was diesel). About 5 miles down the road truck lost power to where it won't move, engine was knocking loudly, and belching white/blue diesel smoke. Found out truck was low on oil so some was added. No change. Pulled it home (won't move at all under it's own power). I haven't been the best about changing the fuel filter, but tried changing that to no effect. HPOP reservoir is full to within 1" below plug. (guessing HPOP is functioning OK) I can open the fuel bowl drain and turn the ignition on and get LOTS of fuel flowing out of the drain. (guessing fuel pump is OK). Any ideas on what to check next? Here's a little incentive to help - if someone figures this out I will send you a $5 Starbucks gift card (or your favorite coffee shop). I really need this truck to run and right now can't afford to get it towed somewhere to be fixed.

Here's exactly what it does now:

Cranks fine, glow plugs work fine, starts as normal. Runs a little lumpy right after starting. About 10 seconds later the engine starts knocking loudly and the diesel smoke starts billowing out of the exhaust. Throttle pedal has no effect on engine (won't increase RPMs). Will run like this indefinitely, but will not move. Oil pressure ok on gauge.

Truck is in central Iowa if that matters.

Thank you in advance for any/all help. I'll answer diagnostic questions as quickly as I can. I've looked through the archives but haven't seen a truck with these exact symptoms.