TPF chemotherapy treatments

Hi, I am new to this board... I apologize in advance for giving so much detail and for the lenghty post... My father is in this 3rd round battling tonsil cancer. First round major surgery followed by Radiation; knock out, cancer free 10 years. 2nd round Feb this year, further surgery not an option another round of Radiation which he hit his max 10 treatments from completion. no signs of cancer through Aug 12th. We found out that between the last week of July and to date, it spread from original site through lymphatic tissue to other tonsil and toward the ear.
Now, he is facing TPF chemotherapy. Does anyone know what we can expect? He is at the point where he is having tremendous pain when swallowing and is on pain med just to dull it. I am very concerned due to the fact that he cannot tolerate vomiting at this point.
Exactly how harsh is the TPF. He has lost a great deal of weight the past few weeks and does not have any left to spare. If anyone has information, I would truly appreciate it.