It's such a hard thing to see. Minnie died from renal failure also (actually, from a seizure caused by it). And she shook in pain any time she drank once she got it, which was tough because we had to feed her tons and tons of water due to her absolute minimal kidney function (we put chicken broth in the water to get her to drink a lot).
I know what you mean about the car keys. It took a couple of weeks before I'd stop instinctively going around the house looking for her. I think I was up 40 hours straight after she died, and I had to make that same horrible decision you did. I mean it was the right one, but it just stinks having to choose between two really bad scenarios. Nothing in my life has been so painful, and the only thing that made it bearable for me was coming here and reading about people's yorkies and telling my baby's story. Reading about
Paris the Blind Wonder Dog was the first thing that calmed me down enough to sleep.
I guess it helps to talk about your great pup to all of us who really love yorkies. The kind of hurt you're feeling is just way too much to bottle up. Hugs, and RIP to your sweet Adonis.