Worried About my Dad

I am not sure if I put the right category or not... I am looking for information I guess to convince my father he is truely sick! About a year ago he was experiencing a infection in his head that hurt to his shoulder. As a result he lost all of his teeth. About the same time or ealier he was having problems with his lymphnods in his throat and swolling. He did had blood work done but it didnt show anything. So now its a year later and he barely can swollen in extreme pain, low appitite, always feeling like he will throw up. He even forgets my husbands name alot. He is 66 yrs old. Feels so bad he is not himself anymore. I am very worried he will die as he will not go to the Doctors now... He is quite bullheaded... Any information you could give me would be great!...What are the symtoms of Throat cancer? note: His father died of lung cancer and just this Spring his sister died of cancer (lung & brain) All I can say is since I was a kid he has always told us he would die like his dad did....Very sad..:O( (He has not smoked for 44ys) Thanks Windee