What is the main conflict in Nobody's Fool by Richard Russo?

Donald Sullivan, or Sully, has lived in New Bath all of his life, like most of the other residents. He is divorced from his wife Vera and is on partial disability due to a knee injury. He does not have much money and has been denied total disability. Despite his lawyer's advice, he decides to return to work and does odd jobs for Carl Roebuck, the owners of the Tip Top Construction Company. Sully has a strange relationship with Carl; the two rag each other constantly. They also have a game of stealing Carl's snow blower from each other.