@tiredofbeingtired, it sounds like the treatment is wreaking havoc on your dad's body. It must be so hard to watch him suffer. Whether to continue treatment or to stop should be the patient's choice. Quality of life should be consider as much (perhaps more?) as quantity. In my dad's case, he was told he was in charge and could stop chemo whenever he wanted either temporarily or permanently. When he stopped, he was told that it was likely he would have about 6 months. He was with us for an additional 13 months and kept comfortable by the palliative care team.

Has your dad been able to discuss the pros and cons of continuing treatment vs palliative (comfort) care? Has he been given the option of taking a treatment break? Do you accompany your dad to his appointments?