I am so sorry my friend, I went through a similar experience with my father, I already knew that his departure could come at any moment, but we are never prepared, just like you I received that call with the news of his departure, we must see that his body is already resting from that disease, because a disease as you describe it is not life.
But we never want to accept it.
Thank you @zhanavic69, it is hard to accept it, but it is ineinevitable.