Hello, 2007 F250 Supercab 5.4 4WD 108,000miles

While towing a heavy load in my enclosed trailer up a slight hill the truck started to buck a little and barely did 30mph. When I pressed the pedal to the floor it bogged down badly and almost stalled. Limped to the exit and almost didnt make it home. Check engine light came on. Started searching forum for diagnosis.
Codes p0171, p0191
First thing I did was change the fuel filter. Old one had black coloring dripping on paper towel. Pulled battery cable for half hour then test drove. I got on it..Pedal floored...passing cars and accelerating was back to normal. Problem solved I thought. Hooked trailer back up and headed north(goin to Maine) After an hour drive with no problem at all the same thing happens and check engine light comes on again. Limped to a close by autozone thinking filter has got tank debris in it. Replaced the fuel filter again and got codes read. Same codes....pulled battery cable again to reset computer. Made it almost all the way home and problem happened again. Read all the possibilities..heading to Stealership monday but wanna rule out some things.

Probably should have plugs changed since 108,000mile..PITA to DIY
Should clean fuel injectors and MAF sensor.
Added dry gas to tank
what else can I do as to not get jacked with $$

Cats dont smell or glow
Mufffler is good and not falling apart.
Engine ran great and strong till an hour into the drive(happened x2)

Any help thank you in advance