Very sorry to learn about the terminal stage of the cancer in your father.
Unfortunatley Throat cancer
is one of the killer cancers because you can't normally detect it until its too late as the patient doesn't feel the symptoms until late. unfortunatly it is a very painful cancer as the patient intheory starves to death and it can be very uncomfortable, morphine
will help mellow the pain. during the cancer the patient will slowly lose the ability to swallow although he has been fitted with the device now which will help him take the food.
There is nothing which can be done now except giving good moral and nursing support to him and praying to god.