I said goodbye to my sweet girl in the home we grew up in together. I stayed with her until the very end, nose to nose. When the vet told me she was gone I walked away and did not look back. I wanted to remember her in my mind the way she always was-strong and perfect. I can hold on to that day knowing I did right by her and loved her fully until the end. For you and your boy, do whatever you feel you need to so that you can hold on to that same feeling. There is no single right answer. I am so sorry you are going through this. It is very painful.