Tricky Puzzle

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 man’s friend left to get fish. Five hours later the fisherman came back to tell the man that 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 restaurant and ordered salmon,took a bite,froze,went home, and killed himself.
Why did he kill himself?