I don't know about other writers, but my energy always crashes right after finishing a book. Last Friday I put the final touches on Guerrilla Tactics of the American Civil War for Osprey Publishing. Ever since then I've had no energy. Now I think I might have the flu. And I have an update for the Madrid guide due Friday! Ugh. I try to schedule book deadlines well away from any other work obligations, but it doesn't always work out that way.
At least this is all happening at the end of the year. It will be nice to have a couple of weeks with no obligations except what I put on myself. That will give me some time to relax and think about my upcoming projects and prepare myself for my next novel, what Dennis McKiernan calls "letting the well refill."
I know my optimism and enthusiasm will be going strong by the beginning of the New Year, but right now all I want to do is sleep!