We had similar last year. Strong tea with sugar; kaolin and morphine (if you can get it, we couldn't), charcoal - we got it from the chemist and ground it up in the strong tea.
Vet gave him a steroid, an anti-inflam, and antibiotic and a vitamin injection ( I think) - he said it really came down to how much the she.ep had eaten in relation to his bodyweight. All the jags were to make him more comfortable and address any underlying issues.
If you can try and keep him eating, it keeps the rumen going too. Our Dickie survived but we dosed him last thing at night and it was that awful feeling opening the byre door in the morning, fearful if what we'd find - and there he was, bright as abutton and looking for breakfast.
that your sheep is OK too. I think I'd be inviting the neighbour round to see him while he's sick though