My uncle, who had cancer, was not writhing in pain two days earlier when I last saw him. That is not to say he did not have pain. But I believe he would have liked to have remained clear headed until his death. My father, on the other hand, suffered more, imo, because of the morphine. Two nights before his death he stopped breathing for 45 seconds. I told the nurse about this, and her response was to blame me for swabbing out his mouth. At that point, he was not in pain and could still converse with me. I think he too would have liked to have lived as long as he could.
Unfortunately, you’re not clearminded up to your death. Have you ever watched anyone go through the dying process? It’s not like the movies.