(((hugs to both of you) I don't have any answers because we all grieve differently, but I can share my experience with you.

I was where you're at last year. I had to put down my 17 yr. old kitty, ChowChow. I do miss him deeply., I had him since he was a little kitty. but in his case, he was old and in very poor health, and it broke my heart to watch him dwindle from a big healthy 17 lb. boy to 7 1/2 lbs. of skin & bones. I must say, while I mss him, I feel serene about it. I know it was time.
On the other hand, I lost my RB girl, Rosie, over 3 years ago and I still miss her every day. She was hit by a car and died within minutes. She was only 3, and she was my heart-dog. I always saw us growing old together. I thought she would still be under my feet as I sat in my rocking chair - she loved that! I got very very depressed. Star did , too. And it was mostly because it was painful to see Star be so sad, that we decided to go ahead and get another dog. i didn't hurry, and finally found the right dog, Sherman. He has helped our hearts heal tremendously. I can't imagine life without him now, he's so special to us.

I keep one of Rosie's pictures by my bed so I wake up to her smiling face everyday, and say goodnight every night. I keep Rosie's ashes & collar on a cupboard in the hall, I often stop & talk to her. We put some of her ashes under a tree I can always see, and that is also very comforting. i can always go out & touch the Rosie tree.

I know you will both find some special things that will help you cope. the pain never goes away, just lessens with time- they are part of us furever!