My dog is a corgi/terrier mix, and she's about 14.5 years old.

Last year, she developed a bunch of growths along her stomach. Within the last couple of months, she's gone mostly deaf and mostly blind. Within the last couple of weeks, she's gotten extremely disoriented-- bumping into walls, can't find the door to the outside, going potty inside. Playing fetch was her favorite thing on earth and now she can't see or hear the ball (she can smell them, though). I have to carry her outside because she can't do the stairs, and she can't find me once we're out there.

She still seems to be in good spirits. She has a good appetite, she doesn't seem to be in pain, she wags her tail when she's walking around or being pet. She sleeps a lot but she doesn't seem terribly lethargic, she perks up when I wake her up. She's gotten much more affectionate, to be honest.

I'm so worried I'm going to look for excuses that she's fine that I'm going to miss the signs that she's ready to go. Any advice?