Sabbath

I seem to be getting into a habit of writing these blog posts on the bus to work - hence the lack of links or pictures - basically because it's free time with an internet connection. The fact that I don't seem to have time during the rest of the day struck me particularly this morning, because I was already thinking about Sabbath.
My Bible reading this morning was the passage in Exodus containing the 10 Commandments. Now it doesn't matter if you think that the 10 Commandments are the actual words of God, or if you think they're a Bronze Age social code with a tag saying 'And by the way God says this, so you'd better do as you're told'; the point is the same: a day of rest is not recommended, but mandated.
I don't keep this commandment. Over the years I've broken them all except for one, but right now the issue for me is that I don't have sanctioned, agreed, planned-for downtime. Instead what I have is a never-ending to-do list, and hours or days when I think 'I'm too tired, I can't be bothered, I've had enough of this,' and I then do what should be leisure activities while feeling guilty for wasting time.
Of course this isn't good, and I know I should make a change, give myself permission to chill out, even plan a deliberate Sabbath, but the truth is that even thinking about it makes me begin to panic that I have too much to do and not enough time. Planned rest may be such a good idea that ancient societies (or even God) said we should do it, but there are too many things I've got to get done.