Puppy put to sleep help?

I got this puppy at like 4 months old the owner was abusing her well a week ago she stopes eating took her to the vet a few days ago the vet said she has kiddny problems and she still kept getting sicker and we had to put her down today she was only 8 months old it was the saddest thing ever I watched as she slipped away till they said she was dead cryer my eyes out I'm asking anyone any tips to help heal me I'm so depressed I had to put my puppy down a black lab by the way but I just want tips or advice to help me get through this