Fishy Situation

Question: A man and his friend is on a deserted island with a fisherman. They needed food or they won't survive but their row boat would only carry two people so the fisherman and the mans friend left to get fish. Five hours later the fisherman came back to tell the man his friend drowned and the man (we'll call him Cody for now on) ate his cooked fish depressed. Many days later Cody was rescued by a rescue team. He went to a formal resternaut and ordered salmon,took a bite,froze,went home, and killed himself. Why did he kill himself?