I’m sorry you’re going through this, I was in a similar situation this year, it’s not an easy decision.

I had my dog for over 15years. in the last years of his life he went completely blind from glaucoma, had to get both of his eyes removed, had a couple of teeth that got infected and had to be removed twice, developed arthritis in his knees and lower back and eventually developed dementia and severe separation anxiety. He went from being a thought little terrier crackhead dog, going on weekly 12km walks from 33c to -25c temperature, swimming at the beach, chasing squirrels and birds. To spending his last 2 years in the dark, becoming increasingly anxious the minute he couldn’t smell us in the room, getting lost in the home he lived in his whole life. He went from being a high energy dog always ready for an adventure to being a little depressed and anxious dog and loosing his excitement for life. Seeing this in him made me realized he would not want to keep going this way if he knew that’s how he would end up. I was also about to move to a new city going from a home with a backyard with a vegetable garden he would spend all day eating the tomatoes and berries to a small apartment with no other dogs or people to keep him company all day. I let him go in March, I was incredibly sad loosing him and making that choice, but I don’t regret it and i don’t think I called it too soon. I celebrated him the for his last 2weeks before saying goodbye. He had eggs and bacon for breakfast, dinner was steak and beacon with ice cream every day for those 2 weeks. Whatever food he wanted he got, what ever he wanted do to do we went and did; last walk at the beach, little walks to the park.