Fifteen years! That's a long time to make you happy. And for bonding.

It was douchey of your family to do everything as they did, but then again I can maybe see their reasoning. You would have had a bad time and would have come over just for that reason. And telling someone who obviously cares that something bad has happened is difficult as well. Yes, this is bad reasoning. But ultimately it didn't matter. He was old, very sick and if we're going to adhere to putting down our animals humanely when it's their time, stalling does not make sense. So there weren't going to be any goodbyes which would feel real.

But then again I'm not sure there ever are.

Please don't feel responsible. It's okay to feel sad about what happened, but you had no say in any of this. Coming to visit you is not something weird. Not coming to visit you would be weird.

And no, there won't necessarily come a point at which you can say - "I'm over it." Once you're close enough to an animal, they don't really differ that much from people. It hasn't been that long since he died. The pain will, by some time, become numb. However, hurting isn't necessarily bad. You still did have good times with him. In his eyes, that was his whole purpose. You know that. You both succeeded in your roles. This is good.

At some point, you will arrive at a place in life where you can get (adopt?) a new dog. If you can rely on yourself to care for it, don't hesitate. They won't be a substitute for Shadow (what a cool name!), but that's not the point. They'll try their best to be the best damned dogs they can be, and it'll be awesome. You'll perhaps even learn to appreciate what Shadow was. A new dog won't compete for your old affections, they'll supplement them.

Shadow did his part. Now you do yours. Hang in there, friend.