I do not believe this is something he can wait a week for treatment for, especially since he has been getting progressively worse over the last few days.
You *MUST* find a way to get him to a vet. Pawn jewelry or anything you are able to. If you cannot get him to a vet and he continues to decline, you will need to surrender him to a shelter, vet or rescue. I know that is NOT what you want to hear.