My heart goes out to you. Its like losing a member of the family. It takes a long time to get over and its very hard.
We lost our family pet a Lhasa apso (got her when I was 7 years old and she passed away when I was 21) that was 7 years ago now and its still very sad. When I visit my parents I still expect her to greet me at the door.
My hubby and I have a dog now, another Lhasa and I cannot imagine what will happen if anything happens to her...
I am sure you gave your pet a good life and made sure they were loved and just keep that in mind.
Chin up.

x