I understand your anguish. I have never been so devastated in my life. My dog died suddenly and she was only 6. Still don't know why...heart failure, aneurysm, embolism...those were the best guesses. Shock on top of grief is the worst. Your dog was 13 but I understand you thought things were going well. I would have been angry too about them being left overnight. I just realized that about my vet as well when I was there. But they had told me that when they closed I would have to transport her to the emergency vet since nobody was there and they knew she was critical. Then they said she was stable and I was hopeful, they said I could pick her up at closing and take her home instead of to emergency. An hour later she crashed and she was gone so she didn't have her final night in a cage. I understand your anger, but anger and guilt and what if's don't bring them back. I'm still trying to grasp that. My dog got xrays, fluids and bloodwork $700 for that, $150 for cremation and box. I would have spent anything though to make her well. You did what you could. I think the road to acceptance and peace is longer for some of us and longer depending on the bond with that person or animal. This is the worst grief I've ever experienced over this dog. I had lost others and been sad, but not like this. It's hard. That's all there is, I dont' know about time either. It's only been a month for me and I'm still crying every day. I think sometimes you have to force yourself to go through the motions and find something else to think about before you brood and dwell and make yourself fall deeper into despair.