I'm so sorry, that sounds so incredibly hard. I'm not going to "at least" you, but I am glad he wasn't suffering at the end. Quick is easiest for them, and hardest for us. Lots of hugs as you grieve.
I'm sorry that you didn't get to say good bye, but he knew he was loved by you and his family. I'm so sorry for your loss. Doggy insom is getting up there in age and I know that soon we'll be going through the same thing.