Today's Public Service Announcement: Beware of Bad Gas
In this cold and nasty weather season, gasoline - ESPECIALLY the shit with ethanol in it - attracts moisture. Moisture is water. Water, contrary to about a brazillion YouTube videos, is not a good motor fuel.
If your car starts sputtering and acting like it's about to run out of gas at low RPM when there's a lot of it in the tank, you have Bad Gas.
If you have Bad Gas, take thee directly to the first place you can find that sells car parts (in this case, even Walmart will do) and buy a container of high-quality fuel system cleaner - not the house-brand stuff, but something that costs $10 to $15 per bottle - put all of it in your gas tank, and drive around until the sputtering goes away. Then go to a name-brand gas station and top off the tank. Drive the car until you're at a quarter-tank, then put another bottle of the same cleaner in the tank and top off again. This will correct the problem.
If you have a car that has an accessible fuel filter, change that too.