Hi thanks for writing to heath care magic.
I feel sorry for what your dad is passing through.
Since you have not put here any of investigations of your father, it is difficult to say, what is the stage of lung cancer
of you father and more difficult to say for how long he will live?
From stage of cancer one can predict how long patient will live.
The symptoms of father which you have put here, all indicates that he has advanced disease and may not live long.
Hope I answered your entire question.