Thank you all for your very kind replies, and the vibes and the hoping. I honestly really appreciate it.
I'm sorry I'm too tired to reply to all of your messages. Casper's doing pretty much the same as last night. He'll eat fresh herbs, and he's eaten some dried forage as well, and some pellets, but he's clearly not feeling well, and not eating normally. Each time I woke up throughout the night I gave him some fresh herbs, and he was eating from the bowl of forage I had left for him, too, so he's been eating, and this morning I syringe fed him. We have an appointment at my own vet early this afternoon, so I'll keep you all updated. I don't know how I'll manage that, becaue I'm sore and very exhausted from yesterday's vet visit, but I'll try to rest until then. One thing I noticed when I was syringe feeding Casper earlier was that he kept making snorting noises, like his nose wasn't entirely clear, so I'll mention that to the vet.
I've looked into complaining about the vet, but he owns his own practice, so I'm not sure how useful it would be to complain to him. I haven't found out yet who I should tell about the no-mask thing, but I did find out where I can complain about the poor treatment, and it's a long and involved process and, sadly, I just don't have the energy for that...
Oh, no, I'm so sorry you got covid on top of your ME! That must've been awful... How are you doing now? Thank you for the advice about the saline solution. I looked up how to make that and I did that, since it didn't seem like it could hurt and might help. It was very gross, haha. Thank you for your wishes for Casper and me.