Check that screen in the sediment bowl. See if it has a dull grey "dirt" look to it.
If there is any crap floating around in the tank (usually supplied from the pump return), it's gotta come thru that screen first, even before it gets to the filter.
Once the tractor gets to the point of the dying/starting/dying thing, then we gotta look at that pump.
However, what you are describing is just plain ol' fuel starvation.