OP, I’m very sorry for your loss. That is just so sad. It’s beautiful that you and your family are taking so much time to go through this grief and comfort each other and pay tribute to your beloved dog. And yes, I do believe that all dogs go to heaven, and I’m just really sorry for your loss!
We went through something similar with our Westie on Dec. 23 a few years ago—talk about a horrible Christmas.
If it is any consolation, at all, just last night my dad and I were talking about the fact that we are thankful our Westie did not have a long period of being in pain, or confused, or weak and listless, like our cairn terrier did. We had two older dogs, and one had a long and slow process, and the other one died quickly after a brief illness. Looking back, having experienced it both ways, limited pain/illness was a blessing for our dog and for our family—no hard decisions, no difficult weeks, no bedtimes knowing she was in distress.
You did your best and loved and cared for your dog for his whole life. A good dog, a good family, a good life, and even a good grief in that you are allowing it to happen, supporting each other and honoring your beloved pet.