Writing Fatigue

I don't even know how many hours I spent writing today; between three and four.
It's the graft bit now.
There are about 60 books stacked up there, and a whole pile of academic articles plus lots of data.
I've written just over 20,000 words, not counting the interviews.
What I'm writing is depressing at the moment; I'm hoping to get to an 'up' bit soon, which will probably be editing the interviews.
Now I'm writing therapeutic songs!