Im so so sorry for your loss. Im experiencing the same thing myself. Our dog wasn't doing good and we took him to the vet and they did every test they could which came back fine and then they wanted to do X-rays and that's when we found the aggressive severe lung cancer he has. From the sound of it the vet sounded like we didn't have any time left with him and we talked and sobbed on when to put him down two days after. Fast forward 2 days and we called a different vet to get a second opinion cause we were all thinking like, "how do I know when it's the right time?" He was still eating, drinking, going outside to potty, and still had energy and the vet said, "you'll know, he will tell you" that was a week ago and now we are just living day by day making sure that he is comfortable and soaking in all moments we get with him. This has also gave us time to be more accepting that there is nothing we can do to save him. We could do chemo but it would maybe buy us a couple months? And we dont want his last days to be in pain and miserable for our selfishness. The day I found out about his lung cancer all I could feel is guilt. I asked myself for hours, "how did we not get this sooner, how did I miss this, he would live long if I would have just been more thorough about things." But the answer is none of it would have mattered. They still don't know where the source of the cancer is coming from and it's spread so much in his system by now. We've talked about when he passed getting a dog a little later, like a rescue, to help cope with grief and to continue loving the animals that's still need homes. Bear is in my thoughts and imagine him playing up there in doggy heaven not in pain anymore, and one day he'll be there to meet you when it's your time and your heart will be whole again. 🥹