mamabear,
Really, take him to the vet. Why on Earth would you want to have an animal living in misery?
You're afraid you'd be told to put it down? Isn't that better than suffering? Do you really want him to suffer and be in pain? You need to take him to the vet. Don't worry about tests or money right now. You don't know what the vet will say. Just take him!
You need to do the right thing and take that poor baby to the vets. As of right now, he's got no quality of life.
I would definitely take him to the vet - it could be something simple. I honestly think it will be for the best. Otherwise, the poor little baby might end up suffering. I will say some prayers for the little one. Please let us know how he's doing! Hugs, Janet