A quiet week

I don't know how to describe it but it's been a really bad week - flat, dull. It's not that I've felt ill or there's something wrong - nothing like that. I'm not sure that it's even anything in particular. Just a general feeling of lethargy. The weather isn't helping. That's been dull and flat this week too. The clock change is probably what it's all about really, the dark nights and increasingly dark mornings. How SAD is that?