My Grandfather, a christian scientist (pray to god, get real life healing results, once ate poison oak to prove his faith to himself, he was fine btw), denied all medical diagnosis/treatment on his deathbed, up until the last few days when he was prescribed some kind of opiate to ease his pain. He literally wasted away, lost nearly half his body weight, and made it right up to deaths door without taking a drug in his 81 years of life.
Fucking badass if you ask me, and i don't think any less of him for needing some kind of relief in the end. I just wish me and my brother took the opportunity to offer cannabis instead of pharmaceuticals, that made him not quite himself, but to be fair herb could have had the same effects.
Personally, i would just consume massive amounts of cannabis, nothing else. And on my deathbed share a lsd trip and a joint with anyone who cared to join in. But that would only happen if i was unable to find my own way to deaths door on my own time/terms. Perhaps sunset atop a rockface cliff while on mescaline, with close friends/family. At dusk, i would say i love you all, all of humanity, how much i apprecciated all of your contributions to my life, and wish all things the best of luck, before spread eagling backwards to my inevitable passage.