Thank you very much for your responses.
I managed to get a fair bit of Critical Care into him (he has 3 feedings since) but he started to ādo betterā in the middle of the night. His ears felt chilled so I gave him a hot water bottle wrapped in a towel.
I got no sleep last night checking on him and petting him and telling him how he is so loved.
He became more alert and aware of his surroundings rather than the distant stare he had in the last afternoon/evening.
Got him into the vet early. His heart beat is strong and the vet examined his belly. He found nothing. From an exam, there is nothing physically wrong with him, besides a bit of a wet nose. And that isnāt āsnottyā, but just wet. Going to treat it as the beginning of a respiratory infection and see what happens. Baytril 2x per day.
The vet pulled blood to do a panel too.
Bunny is still not eating but he is much more alert. He spends time grooming and he still has his balance. He is not 100% himself, maybe like 25% himself, but he is āstable.ā
When I was rearranging his enclosure to make things more accessible for him, he hid behind the sofa (his den spot) and came out for one little hop to see what was up.
He is just pretty miserable right now, but not weak/limp like he was last night.