A big part of his anger came from the murder of the King of Thebes, Laius, his father. Part of Oedipus believed that he had killed the King, however he refused to admit it and displaced his anger into blame towards Creon. Doing this, Oedipus caused many people of the city to lose trust in him.
He also displaced denial into anger. For example, he shut down the oracle, when it said that Oedipus slept with his own mother. Oedipus could not believe it, and would not