So sorry for your loss Eye, sending you good thoughts, it's not an easy thing to have to go through. My Lab Sonny was the same way after we had to say goodbye to his sister, Daisy. He was the youngest of all the animals we had, and when we first got him we had 3 other pets. So he was lost for awhile being only him. I work from home anyways so it's me and him most of the time, so being around a lot helped him move through things. Your boy will be ok, it just takes time and lots of treats, lots of walks, lots of love. It's all you can do.