How do you deal with an 'on the way out' pet?

ugggh, renewed old memories... Roxanne (Siberian Husky) was a little over 15 when she went down. I had her in the basement overnight because she was sick, disabled, pooping on herself. The next morning she was in worse shape. "I'll be right back". When I got back to the basement I found she passed before I could get my clothes on and take her to the hospital. Big hole to dig. Remnant of a vinyl fence project put a cross on her grave. Then 2 years without a dog. The next one, Nikita ( Alaskan Husky ) was a little over 15 when she went down with neurological problems. Could barely stand or walk. Pooping on herself too. Vet at animal hospital said, "steroid injections might get another year with her but there is no guarantee". Only other option is end her suffering now". I paid to end her life with injections. Wife and I held her paws and cried while she took her last breath. They brought her to the car in a cowboy coffin shaped heavy cardboard box. After I dug another large grave beside Roxanne ( keep in mind the ground in the woods here is like digging through red bricks, especially in winter ) I simply could not find closure until I made her a cross just like Roxanne had. I didn't have the needed materials. A few days later, I went to a local fence company, told my story. The guy there gave me the small amount of materials I needed to make that cross.
So I'm guessing that you haven't lost a child. My parents haven't either. I did not hear condolences from my mom or dad when Nikita or Roxanne left us. When their little poodle (Max) left them after 12 years, my mom called to apologize to me before I could call her to express my condolences after hearing Max had passed.
So I truly understand how loosing a pet resembles loosing a child. It hurts like hell! Mom and dad are still dealing with that hurt. Yeah, Max is in their backyard too. He has a headstone marker (my sister had it made) and flowers around. At their age they wont likely have another pet.
I took out my dog fence, sold dog house, fencing and all. Wasn't going to go through this heartache again. Then later on our grand daughter took in two rescue pups. Wife and daughter decided who would adopt which. This little Yorkie/Cocker mix house dog is a heck of a lot different from those large in or out dogs we have had over the past 32 years but... we love her just the same. We know she loves us too. If/when the time comes we will show her the same compassion. Yeah we'll cry, but we'll live through it.
In the end, I don't know if you have a place to bury your pet. You have to determine what is more important, pictures of dead presidents, or your sanity tomorrow. Everybody has their own priorities, It's just a cat, It's just a dog. If it wasn't more than that, we wouldn't be reading about it here in the first place.
If you want a pic of the 2 vinyl crosses in my back woods, I can do that. Next time Miss Gracie and I go that direction.
I say, "Hey doggies". Does Gracie know who I'm speaking to or not? I like to think she does.