It is indeed a major loss to lose one's best friend. My wife calls our dog her best friend. She makes us laugh all day long. She literally runs our whole house. She is smarter than all the dogs combined that I had, and she senses everything. If one of us is down, she knows and does things to support us. Is it so endearing.
My wife was on the verge of crying one day in the kitchen, over work related crap, and the dog sat next to her looking up and she started to cry in a tone that was very unique. My wife was so upset she did not notice until I pointed it out to her. It made my wife go from tears welling up in her eyes to joy at seeing the dog sense how she felt. She bent down and picked her up, hugging her with great joy.
I cannot imagine being here without her. She has become such a prominent force in our lives. Yesterday, she jumped on the bed and woke me up, telling me it was time to get up. She often does this. She is so funny. I think I mentioned this before, but she will give a little hmmmf, and does it 3-4 more times a little louder each time. She woke me up with the first one, but I pretend to sleep, so she nudges me with her paw, and I stay still, and she nudges me 3-4 more times, a little harder each time. I still lay there pretending to sleep. Then she pulls the bedspread, blanket and sheet down to the foot of the bed, and by then I just can't keep a straight face. She is a real hoot. And she is always very serious with her looks when she is doing this.
So, my sincerest sympathy for the loss of your good friend.