We just had to put our 15 yr old Chiweenie down before going on a long international trip the last week of May. He had what I would call "roller coaster" dementia as he had good days and bad days that got progressively longer in duration to good weeks/bad weeks. He was deaf and almost blind, and in early stages of kidney failure. Last time we went on an extended vacation, he quit eating and lost about 1/5 of his body weight. Other than looking scrawny, he was otherwise heathy looking and appeared his normal self and jumped and hopped for treats. Over the past few months he suddenly started relieving himself in the house, had trouble negotiating the doggy door to go outside, and when he did go out, he would barely venture into the grass. One of his favorite things used to be sunning himself in the grass or on the patio furniture, but he stopped that many months ago for some reason. He would yelp if anyone touched him suddenly, like it startled him, and likely had arthritis pain. A lot of tough discussions with the family before we came to the conclusion that he likely wouldn't survive us being gone for two weeks, or if he did, he wouldn't be the same and it would only accelerate his decline. Such a brutal decision, but it had to be done. My youngest daughter is 18 and was very attached, and this was her first true death of a close family member to deal with.
I pray your dog gets better, but hearing what you are dealing with it sounds like you are unfortunately postponing the inevitable. We felt more frustration and anger than joy towards our dog during the last month and knew it wasn't fair to him or us, and didn't want to tarnish the good memories we had of him growing up with our family. It's guy wrenching when it's time to make that call. God bless.