Without hearing your rough run , I can't be sure, but with what you describe , I'll put money on bad fuel , changing the filters and cutting the old filters open would be the first and cheapest step, to checking your problem out.
If contaminants entered the tank at the fill up, it would have taken the 150 miles for enough fuel to go through the filters to plug them. Possible that the contaminants just needed the month long shut down to grow in the filters & tank.
There is a return line pressure valve at the back of the cylinder head , but problems with that usually result in no start, no power condition.
The alternative ; well you don't want to hear; HEUI pump failure.
Read about this in the Cat engine section of the power train forums.