I'm sorry for your loss. People don't always understand, but losing a pet is losing a family member. I wish I had a quick fix for you, but I would recommend you take a couple of days off, try to find happy pictures you have of him, talk about the silly things he did with friends, and let yourself grieve. Covering up the feelings with work or activity may help in the short term, but there is nothing like taking the time to grieve. He sounds like a great dog, may he rest in peace.