@kickycan,
I just had the vet put my sweet cat, Dolly, down, and even though they came to my home, it was the hardest thing to do. She was only 6 years old, but she was disabled from birth, and she was no longer able to control her bowel or kidney. It was doubly hard because she was so young, and she was such a trooper. She could still jump onto our bed as well as over the pet gate we bought to prevent her trying to go down the stairs, but she would jump it, sit there a minute to recover from the jump, then she would literally fall down the stairs...this happened over and over again. And when I would go upstairs, she would crawl back up the stairs. If I was only up there a few minutes, I would carry her back down with me. I love her still and I miss her beautiful green eyes and her sweet disposition, and, yes, I will forever feel guilty for putting her down via euthanasia.