I'm really sorry to hear about your dog being sick.
My first suggestion would be to get to the bottom of what is causing this sudden onset of kidney/liver disease. Is it something the dog is getting into? Have there been changes in food or surroundings or any major upsets in the household. Until you figure out the cause, you'll only be treating symptoms.
We've had this situation happen twice.
First dog was a rescue lab mix who had been abused. After we'd had her 7 years, she suddenly developed kidney disease. The cost of keeping her at the vet's to be on IV fluids combined w/ her terror of being away from us led me to ask our vet to teach me how to do sub-cutaneous fluids w/ her. It's not as quick a fix as IV, but I could do it at home, as needed; saving stress on the dog and our budget. Turns out, anytime we had a change in our household like DH returning home from a deployment this dog would go into kidney failure. Using the sub-cu I was able to get her through a cross-country move, and 2 deployments..... she lasted another 2 1/2 years, well beyond what the vet expected. And she never had to stay at the vet's during that time. But I did have a vet who was willing to work with our situation... that's an important thing, just like w/ human doctors. When we moved I "interviewed" several vets to find one that would work with our situation...
With the other dog, I switched him to a lamb & rice dog food and within a week we had to put him down due to severe kidney failure! Needless to say, I'll never feed another animal that brand/type of food again. Don't know whether it was something wrong w/ the food, or just that particular dog's reaction, but it's not worth taking the risk KWIM?
I hope you are able to get to the bottom of what's causing the issues and also either work w/ your current vet, or find one who will work w/ you. Do you know any other dog/pet owners you could ask for a recommendation?