Yes, his grave condition IS worsening. His lungs are filling with fluid and it makes it hard for him to breathe when he lies down to sleep.
Though it won't be solving the underlying problem, perhaps some (or some MORE) Lasix on a daily basis would allow his lungs to clear somewhat.
Some people can fall asleep just LOOKING at a Lazy-Boy!
Probably KenKeith has some suggestions on how best to extend his remaining time and make it more pleasant for both of you.