I was going to write a post on this last night - but was too exhausted. The irony was that it was only after I stopped thinking about writing a post, other work, the bills, and life in general - could I actually understand and enjoy the point of the break :-P (it wasn't to think and strategize about posting or anything else haha)
Once we burnout, chances of accomplishing anything go to zero. We shouldn't let ourselves go below...maybe 60 percent, because it can be harder to get up again.
The other thing I've noticed, and maybe it's true with other freelancers and work from home types too - I often feel like I've worked - even if I haven't done anything tangible - if I allow myself to think about work non stop (or reply to every email, every call, etc). Though I've accomplished nothing measurable - I'm still fatigued.
Breaks must be total breaks.I find that when life gives us the most demands - that's when we need step away the most. Maybe it can't be for long - but they are definitely the most important times to make time to breathe and recharge.
Feel Better - and I hope you take your own advice ;-)