Oh hun, I can barely see the screen as I'm reading your post I am so sorry you're having to make this heart breaking decision, big hugs. I have had to do it myself 2 years ago when I put my beautiful cat whom I had for 14 years to sleep, as she was too sick to keep going, even on drugs. I had Pooky since she was 6 months old. She was my companion when I was single, someone to come home to, to snuggle up to, she was so gorgeous and affectionate. I miss her so much even today. I wish you strength and courage as you say goodbye to your precious doggie. Massive hugs hun, just know that she will no longer suffer and will be fit and heappy and healthy on the other side.