See, that's where yer f'n up.
The trick is to take mini-vacations periodically. Three, five, seven, ten day vacations taken often enough can give you a relaxing respite from the day to day grind of saving the world.
I highly recommend that regimen. If you find it difficult to voluntarily take time off like that, if you're a workaholic, say, work something out with the FR staff like I did. They're only too happy to help.