Quick update: so I still couldn't sleep much Thursday night, but by morning I at least no longer felt dizzy, so I decided to go in anyway. Surprised myself, really, but I felt it was the right thing to do. Made it to Buxton and back without crashing, and the job was largely successful, so felt good about it.
Couldn't sleep Friday or Saturday night either - was also pretty ill with some kind of cold by Sunday, but went to church anyway. Don't think I would have normally - think I may be getting a little stronger. Mind you, was also quite keen to get Tony to pray for my insomnia, which was really freaking me out! Is pretty dangerous having such serious trouble sleeping when you drive as part of your job, and I'd never had it this bad before. Anyway, Tony did pray (and stick oil on my head, which he's also meant to do) but he also pointed out that Harry and Maureen, who have a healing ministry, were in the church, so he asked them to pray for me as well. They were very nice - I've never really talked to them properly, although their kids seem very keen on Anne!
Anyway, I slept really well last night - felt wonderful this morning.