Norsegoddess,
Pearl had battled kidney failure for 5 years, and when she was increasingly sick the last time, we thought it was more of the same, and kept treating her with fluids etc. She kept eating and purring, but kept losing weight and acting uncomfortable more and more. That's when I saw the tumor in her mouth and the vet confirmed she had advanced mouth cancer- on top of her kidney problems. At that point I knew she was in pain and would continue to get worse and there was no hope for recovery. So that's when i brought her in and stayed with her...she purred!
The two cats we had die before Pearl faded away peacefully at home with us- one was 20 and the other had total kidney failure....but neither seemed to be in much pain- just fading out. But in Pearl's case, I knew the mouth cancer was painful, terminal, and getting worse each day, so I felt i needed to be strong enough to intervene on her behalf so she wouldn't suffer more.
You are using these last days to shower love on your kitty, and that's as it should be. You will know when the time has come to help her through. Sometimes I think it's more about when WE are ready rather than our fur baby. But that's ok too- you are in it together.
((((big hug))))