In "Things Fall Apart" by Chinua Achebe, the greatest internal conflict Okonkwo has is him being what he considered ideal masculinity. He became known as a great fighter, a wealthy farmer, and a highly esteemed man in his clan, but all of this changes when he is exiled for seven years. He downgrades to sharecropping from his mother's family's land, and he immediately begins planning how to regain his status when he returns to Umuofia. "Okonkwo saw clearly the high esteem in which he would be held, and he saw himself taking the highest title in the land." He feels that his value is attached only to wealth and power.
The way that catharsis is related to Romeo and Juliet is that the moment of catharsis in the play occurs when Romeo and Juliet kill themselves.
Catharsis is emotional discharge after something tragic has happened. The audience usually cries and feels pity after something sad has happened, and that moment is called catharsis. So naturally, when these two young people kill themselves, it is quite sad and the audience feels strong emotions after their death.