To beat fatigue, try to set limits..
My schedule, the only openings for poker are start at 12:00 am tournaments. They're
freerolls, so I can leave anytime. Since I'm up late, I make a lot of mistakes. But I limit myself by being pretty loose, see if I catch, then decide if it's worth it to put in the hours to finish it properly.
The hardest thing is to walk away from the table when you have the "I'm due for some good cards" gut feeling, after a bad run.
If you can set a time or # of
hands limit before sitting down, and playing, that may help.