Assuming you can't leave the place (no other prospects around, family to feed, etc) you simply check out mentally. You do an okay job (no point in overachieving

Assuming you can't leave the place (no other prospects around, family to feed, etc) you simply check out mentally. You do an okay job (no point in overachieving), stop being personally invested in the success of projects, roll your eyes a lot, and find meaning somewhere other than work. And if things get too overwhelming you can always vent to your co-workers who are also stuck in your same situation.