Cabin fever

Got totally stuck this week. Couldn't write. Couldn't focus. Couldn't even concentrate on research. Sleepless. Tired. Had a couple of good solid writing bursts, but not like my usual marathons.
Walks on the beach didn't help. Extra coffee was no use. Watching Food TV made me hungry (there wasn't anything on the History Channel apart from endless hours of mummies or stupid US documentaries like "The Wonders of Engineering" - is the BBC on strike or is it just Mediocrity Month?).
Reading something completely off-topic or web grazing made no difference - although it did fill in the time and I know much more about Queen Victoria's Jubilee celebrations and Pushkin than I did last week. And you never know when that'll come in handy.
It's a new book, nothing to do with pirates, and so I tried to analyse my way around the blockage: behave like a fiction plumber. Connected to the fact that pirate book three was delivered last week? Need to let go before working on something else? Fourth book syndrome? Performance anxiety? Can't write about anything but pirates? Total loser?
Tried printing out the patchy draft and reading it on paper. Made lots of corrections. Bored even myself. Had another coffee.
Then yesterday I had to leave the rock (to go to the mainland cinema for Harry Potter). Sat on the ferry in the sun. There was a manta ray in the shallows.
Before we'd even left the pier, the notebook was out, novel subversion was underway, pipes unblocked and all was well with the fictional world.
Diagnosis: Simple case of cabin fever.
Next week I have to return to the land of the living for a couple of weeks to earn a crust. I'll spend the whole time cursing my wasted stuffed-up week.