Sorry man. They lived a long good life for that breed. My last one made it to 21 years old she would walk in circles. Eventually, she started seizing and her organs shut down. I had her on IV's at home for fluids, and was feeding her baby food through a syringe. It didn't matter she still died. I just wanted to give her a chance when the vets wouldn't do squat.
Current dog I have is diabetic and I give him insulin injections shots every 12 hours. I got him as a rescue. He almost died last week from Pancreatitus. Be careful because that can happen fast and they can die fast from it. He is doing better now.
It sucks losing the furry buddies. They are better than people. People are schemers. The dogs just want food and shelter and they have your back. Just hang in there and you're bada*s for doing all you could for your buddy. You're probably are thinking what else could you have done but don't do that to yourself. Don't question yourself......