Try the following:
Anxious--he took over the throne, not because he was the heir, but because he was the last male relative. He may fear that the people don't see him as a powerful or righteous leader. Along with anxious, I might include fearful.
Stubborn, unyielding and self-serving: He won't change his decree until it affect him personally--when Teirsias says that Creon will suffer because of his decree.
Arrogant: Creon won't take anyone else's opinion into consideration and he doesn't feel he should have to listen to Haimon because he (Haimon) is younger.
Biased: Creon doesn't think he needs to listen to those younger than him. He also doesn't feel women are of much use or have much to contribute.
Antigone is one of ancient playwright Sophocles' most famous works. A tragedy, the play Antigone was written around 441 BC. It is the third of three plays. The set of three plays, the "Theban Plays," depict the city of Thebes and the drama following Oedipus' rule as king.
While the three plays are each about Thebes, Sophocles wrote them for separate playwriting festivals. Dionysia, the name of the annual fesitvals, is an ode to the Greed god Dionysus, the god of wine, theatre, and ecstasy. The festivals were competitions where playwrights (like Sophocles) would present their plays in order to compete for the title of "best tragedy."
Sophocles won a City Dionysia tragedy competition with the play Antigone.
Sophocles created in his play a developed female lead, Antigone, for whom the play is named. As a strong-willed woman, she defies King Creon's decree to leave her brother Polynices (a traitor) to rot on the battlefield. The Greek gods were worshipped by the people of that time, and the gods would absolutely not want Polynices left without a proper burial, a rite deemed essential. Antigone chooses to prioritize her devotion to the gods over following the laws of King Creon, so she goes out and gives her brother a proper burial.
Although Antigone is supposed to be married to Haemon, Creon's son, King Creon still orders that Antigone must die for her actions.
Antigone is marched to a cave to be imprisoned and starve to death. By the time King Creon changes his mind, due to the words of the prophet Tiresias, Antigone has committed suicide.
While many choose to view King Creon as the villain, it is important to consider his perspective within the time period. As a brand new ruler of Thebes, his first actions as King would set the stage for how he would rule for the rest of his time as King. If he had buckled under the pressure to let Antigone go free, the other subjects of his rule would potentially believe that he is not strong and does not stick to his rules. His decision to convict Antigone is an action he takes to prove to his subjects that he is a steadfast ruler who will not crumble under pressure.
While he does make some questionable choices such as denying Polynices a burial in the first place and refusing to initially believe Tiresias, Creon also proves himself to be strong in his decision-making. He only changes his mind once the prophet tells him the future if he allows his decision to stand.
Thus, you might characterize Creon as "steadfast" and "a ruler who stands by his laws." He can also be characterized by his negative traits, which include being stubborn, lacking mercy, and being too self-absorbed (since he refuses to bury Polynices even though it will displease the gods).
I would also suggest considering LOYAL as an adjective. The reason for this is that he, though stubborn about his position as king, is in fact loyal to that position and to the decree that he has made. He made a decision and is not about to let his family become a reason for him to falter in his decree. Though we do see this as rather brutal, it does show him as being very much committed to his kingdom.