Hi, I lost my mum to lung cancer in February it spread to other organs, the oncologist department advised against treatment they told my mum to go home and enjoy everyday and have quality of life. Chemo makes you sick and ill. She had no treatment and lasted the exact time she was given by the doctors.Mum didn't want to be sick or drag it out.  Your dad may have been advised the same and is protecting you. Enjoy every moment and make wonderful memories. Life is short. It's the family that's left behind that suffers. I send my best wishes to you and your dad.