I have a dog that I love so much and it would kill me to lose him. Someday I will. I am so sorry for your loss.
When I was drinking my dog was one reason I quit. I became convinced that he didn't love me and that he hated me for what I was doing (project much? lol). I also couldn't connect with him. I'd pet him but then be like ugh go away! (this closely mirrors my relationship with people as well, I know you're shocked)
This is how I think about it: Your dog deserves your full unmitigated grief, because he gave you his full love. If you drink then you are not helping yourself not feel, you are cheating your dog out of a owner that is fully present for him, even if it's in his death.
Take care of yourself.