I went to a Pain Management clinic and said to the consultant they would not let an animal suffer like this (as you have said) and he said that an animal would suffer the pain as they would have no choice in order to survive!?
Way to go - to compare a human being to wild beasts. Well, when they get sick and can't fare for themselves, they die very fast. It's never a nice way to die, but they don't go on being disabled and tortured for years.
Also, wouldn't it be more appropriate to compare you to our pets? We take care of their needs, and when they get incurably ill and start suffering really bad, we bring them to the vet. BTW, we don't shame them and we don't think "poor me, this animal is leaving me all alone, he's hurting me so bad, poor unfortunate me!" We do what we need to do to stop the needless suffering. After that, I felt relief because my budgies didn't suffer any more. It didn't even occur to me to think about myself at that time.
I'm so sorry you have to depend on callous low empathy doctors for help. I'm in the same crowd - physical illness with lots of physical suffering, and I know that doctors can't care less. I couldn't accept it at first, I kept on at my GP, only to be labeled drama-queen and attention-seeker. It left me so traumatised that now I only deal with doctors for admin stuff and some ongoing prescriptions. I keep this contact to a minimum. I'm also from the UK.