Unfortunately at about 1:30 I woke up in agony with what initially felt like toothache but then identified itself as sinusitis. I took anti-inflammatory painkillers but it took over an hour for them to have enough of an effect that I could get back to sleep (I spent that hour reading, not lying awake watching the clock)
A while after that I woke up again after a vivid and guilt-inspiring dream. I'm not going to describe as I know other people's dreams are famously uninteresting :-). I managed to get back to sleep and then my alarm went off - it felt like it was about 5 minutes later but probably wasn't. (Just to be clear, I'm not blaming the meditation for all that, it just stopped me evaluating the success properly!)
Considering all that I actually don't feel too bad this morning, though I am relieved not to have any afternoon meetings to survive today. I still have a little discomfort from the sinusitis but it's much better - far more than I'd expect if it was toothache, so I'm pretty confident in my self-diagnosis. I'm not sure how well I will resist pigging out today if the tiredness catches up with me, but that is for later.