It may be abvious, but was your truck recalled for the fuel sending unit recall? It may bo corroded as per the recall and shorting out/ stops working after some time.

No check engine light? No sputtering?

Is the fuel pump working ok? You can hear if it's running when you put the key in ignition, turn it to 'on' but not start it. There should be a buzzing/humming noise from the back, that's the sound of the pump turning on.