I know sad isn't it. But on the bright-side lectures are drawing to a close, I've finished writing my exam papers and my classes aren't too large, so marking will not be a huge drag. Then there's the semester break so I should be able to get back to some productive work on the book.
In the meantime I'm gathering information and working things out in my head. When it's ready I'll be ready to write it down - that's how my mind works, it processes in the background and then lets me know when it's ready deliver. I learnt along time ago to trust it and let it take all the time it needs.
I came across a excert from Bill Bryson's new book in the Guardian yesterday. I have to say I didn't think it was up to his usual standard, not very informative and not as entertaining as his usual writing style. This encouraged me.