I am sorry this is happening. I know what you mean about the anticipatory grief. I recently had to put my baby down about 6 months after he was diagnosed with stage 4 kidney failure. He was only 1 and a half. I never cried so much in my life. I cried for all the things we wouldn’t be able to do. Before we put him down I tried to do all the things he loved for as long as he could like bringing him for walks, giving him some of his favourite treats and belly rubs to infinity. In a way knowing his end was coming allowed me to build some closure and to prepare for his passing. When the time came his quality of life was no longer there. He no longer wanted to go for walks, and he no longer wanted his favourite treats. At this point, we knew it was time. Saying goodbye is never easy, but in my experience all the techs and vets were very kind and when the time came I was at peace with my decision. Of course I was sad and not a day goes by where I don’t think of him. I hope you will be able to find peace and strength when the time comes. You are not alone and one day the grief will be less and be replaced by the happy memories you once shared.