I too had surgery after radiation when I was at my lowest mentally and physically. While I was younger than your father, and the surgery was less extensive, it sure took the wind out of my sails. But here I am 5 years later to talk about it. If he is scared he is normal, all the things you mentioned that he went through after radiation were normal for a typical patient as well. If he needs to talk with someone, have him contact me. I will give you my number by email if you like.