Swati, all the advice you have been given is excellent. I would add that if you can do it, it might be a great comfort to your father to tell him that it is okay to let go. Different circumstances entirely with my mom, except she too, was kept doped up because of the pain, but when my dad and I finally realized that she would not get better and was fighting only for us, we both told her it was okay to stop, and other personally meaningful things, and she died within hours. We were very sad, but also glad that her terrible battle had finally ended. I felt better that I was perhaps able to set her mind at ease somewhat by letting her know that I would be okay. I am not sure this makes any sense, but it did help our family. You and your family are in my prayers.