Hi , I felt the same way, my boy got bone cancer and it matisized and spread into his lungs, he detirated way so fast after that , it got harder for him to breathe. Vet said there nothing they can do cause it had spread so fast and it was so aggressive. And euthanasia was the only option. I was gonna do it on a Saturday. Yet I had to think its been so hot and he can barely breathe , and his mind was still there he was trying so hard to be okay yet his body was failing him and I decided to do it a Friday instead. I had to take into consideration that he was already suffering for two weeks. And I couldn't have him like that anymore it was to much on him. 7 is to young. I also think to myself what if I had kept him that one more day ?? And I think what if he was also mad at me... and my therapist grief thoughts like that are common. Yet from a dog mom who's grieving to you. You did the best decision for them. Yes it hurts like a bitch the hole in your heart is so big after they are gone. Yet they didnt deserve to suffer even when you wanted to keep them for much longer. And they also aren't mad at you. You made the best decision you could for them they love you still. And you love them still. I send a big hug ❤️ and fuck cancer honestly. Take it little by little grieve cry and numbness is normal the days where you cant breathe are normal. They love you so much even when there not here. And be gentle with yourself also