I am so very sorry for your loss and I know exactly how you feel.
I had to do the very same thing for my Rebel Cat about a year and a half ago and it was heartbreaking. She was 18 years old and had been with me longer than any living, breathing thing. We had been through so much together and when I noticed that she was failing ... it broke my heart.
I hope that you are able to find Peace where there is pain and I promise you that it WILL get better.
Perhaps not right away, but in the near future, you will be able to remember her with smiles and fondness .
God Bless ....
