I'm so sorry to hear about your puppy (all dogs are "puppies" to me, regardless of age ;-))...what a cutie!
We just lost our dog about 2 weeks ago. We had her over 10 years, and I was really devastated, especially since the end for her wasn't easy. She was blind for a few years now, had diabetes, and we're pretty sure she had cancer too. Her back legs were giving out on her now and then too from arthritis. We knew that it was getting close to her time, but nothing truly prepares you for when it happens. We had kind of hoped that when it was her time, she'd pass away quietly in her sleep, but instead, she had some kind of blood sugar related incident that left her with brain damage. She wouldn't eat or drink (I suppose she didn't even know how with the brain damage), something the vet said she'd probably never recover from if they were able to do some intensive work on her (basically, she'd be a vegetable), and she got dehydrated. She couldn't stand on her legs, either. Worst of all, she would cry a bit now and then so I knew she was having some pain during all of this (even though the vet insisted that she didn't even know what was going on and didn't feel any pain), but there was nothing to do for her that could help her or bring her back out of that brain damage.
How can you help a dog with brain damage that doesn't understand the concept of eating or drinking??? The worst part about all of this, was that she was the very best dog I've ever owned I think, and I've grown up with dogs my whole life. She grew up with my son (we got her when he was 2, and now he's a teenager) and was around before my middle daughter was born (she's a preteen). I just couldn't imagine life without her being here, because as long as my husband and I have been together, she's been a part of our lives as a family. I've been dreaming about her a lot, and in my dreams, she's not really gone, but she's healthy like she was in her younger days--full of vitality, and strong, and happy. I'm relieved she's no longer suffering of course, because that was pretty horrible for her, but it doesn't help me to miss her less.
We still have one dog left, but she's getting older too (although at this current time, at least her health is still pretty good). It's never easy to lose a pet when they become such a part of the family. I'm so sorry for your loss, and I hope you don't mind me posting my story. I've really not been able to talk about it much until I read your post.