Dear 1022, very sorry for the news. I am close to your age and lost my boy a few months back. This is what I do. I give it a few days and then go and adopt someone who really needs a home. That is what my dogs that have past demand of me, and I listen to them. I feel that losing a dog is about as bad as it can get.
I'm deeply saddened to hear about your dog, I too lost mine some years ago now, his name was Stan, a Bullmastiff, I swore I'd never have another dog as he was my best mate.
Eventually I weakened and bought an Australian Kelpie, she has never Replaced Stan, but she is also my best mate. Don't giver up. I'm 76, so not a youngster either. A man needs a dog.