Sorry man. I have 2 yorkies and I can only imagine what it would be like to lose one of them.
Our little one (3 lbs) had to have liver surgery this winter to close off a shunt. She started having seizures and going completely limp. It was scary as hell.
Surgery was pricey (like upgraded turbos pricey) but it was worth it. They definitely become part of the family. Find a new puppy soon, hard to be sad around those guys.