I just wanted to express my sympathy for what you're going through.
It's so scary and i'm sorry this is happening to you.

I just went through a nightmare with my cat, who was with me for
nearly fifteen years, after she had some back teeth removed under
anesthesia. Her illness after that was extreme and very unexpected to
me. It resulted in her death about ten days later. I really can't
believe it when i look out and see her grave.

Hug your dog as much as you can. Hold him and give him lots of
kisses. He is at least blessed to have you there to take care of him.