I'm taking him back to the vet tomorrow and we will repeat his blood tests to see if there's been any improvement with him being on antibiotics for the past 3 weeks.
He's still able to drink on his own, but he doesn't eat. Or move much.
On sunny days, I put him in my windows to bask. He loves it.
If his bloodwork is the same or worse, I think it will be time to make that terrible decision to let him go, to stop his suffering. :(
If there's an improvement then we'll keep on keeping on for now. Maybe we can add in an additional antibiotic or something.