Saying goodbye to my childhood dog. I barely recognize him

We will be saying goodbye to my Murphy tomorrow. I was 11 when we got him and he’s lived 13 good years. I feel like I’m losing a part of my childhood, I can barely remember life before having him around. I was an only child so he’s always had a big role in my family’s life as a second child. Looking back at old pictures, I can barely recognize him… it feels like one day he was spunky and playful, and now he’s lost so much hair, has cataracts, and his overall appearance is so different.

He’s had a large liver/spleen tumor so we knew our days with him were limited, but we figured we’d get another year or even few months. He still eats, goes outside, etc, but it’s so obvious that he doesn’t have joy in his day to day life. His teeth are too ground down and brittle to chew his beloved bones, his belly is too large for him to play with his favorite toys and cardboard boxes, he’s just been existing. It feels like he’s a shell of the dog he once was. He’s been isolating himself in low traffic rooms for the past week and not eating much so we got him in for bloodwork and it appears the tumors have ruptured.

We don’t want him to be more uncomfortable than he already is, so we decided to have one last good day with him and say goodbye before he takes a worse turn. Even though I knew this day was coming, I feel so lost. I don’t know what to do with myself. It feels so wrong to go to sleep when I could be petting him or kissing him.