I know the feeling all to well. I have cholangiocarcinoma or bile duct cancer. Unlike yours, it’s rare, about 6000 cases a year in the U.S. It’s incurable and I don’t see the wisdom of doing chemo for the same reasons you suggest. I’ve been researching every alternative treatment avenue I can find. I’ve adopted a completely plant-based diet and have a regiment of supplements I take daily.
I don’t have horses but I do have a dog, and I will be breaking the same kind of promise. I’m convinced he is aware something is awry with my body, something toxic and threatening. His attachment to me has perceptibly grown, and he seems highly concerned about the state of my well-being. If our roles were reversed I would behave similarly toward him.
Best of luck, both here and hereafter.