It takes confidence to take a day off
Someone said this on the @couriermedia podcas once, I really liked it and wrote it on the back of my hand.
When you work for yourself, whatever size your business it can be nerve-wracking downing tools and taking a full day totally away from work. I did it last week even though I was in the middle of a launch. Things hadn't gone the way I'd hoped so I just put the racket down and walked off court for a break.
If the idea of being completely uncontactable work-wise for 24 hours makes you feel tense it's worth considering that you might be running on adrenaline instead of the optimum state of flow which is paradoxically more relaxed but more productive.