My heart goes out to you. I watched my father go without food or water for a week to ten days--his desire was not to have his life prolonged through artificial means, if he couldn't recover from congestive heart failure. He choked on any liquid and had to have numerous lung therapy (tube down his nose to remove the fluids from his lungs) which was very invasive.
Ativan and morphine and 24 hr. watch with one member of the family always with him was how we managed. I know his care was better as someone was always with him. He was comfortable and had no worries-at 88-passed quietly while I was with him. It was hard on the family but hopefully he was comfortable each day due to meds.