That's awful. I've recently gone through a similar process with an aging relative.

Two takeaways for me:

The things the medical industry will do to keep people "alive" are extraordinary, and expensive, and (in some cases) abuses of the concept of "living".

Moving to a sane jurisdiction where assisted suicide is legal is the only possible (but not guaranteed) strategy to approach this problem in a dignified way.

(OK, some people will argue that suicide is never dignified or moral or whatever, but I am not interested in their opinions about what I can do with my body in this situation, or really any others)