I agree with what almost everybody has posted. I learnt a lot about myself in this business. I thrive on it. But every once in a while I get that client that just pisses me off big time. So for me its better to not book too far ahead of time. Also to take little time-outs several times/week.
So from tomorrow I'll finish off work around three and going to chill with someone I haven't spent time with in ages. And I'll be back on Sunday, not necessarily to work but to help a friend's 7 year old with his Valentine's day plans.
When I have on off day the quickest pick me up is to spend time with one of my friends' kids.