Why does Okonkwo have difficulty starting a new farm in Mbanta, and what is the significance of his plight?

Okonkwo's greatest challenge is overcoming the fact that beginning the new farm is a necessity.... he takes no pleasure in starting over. He's older, his wives are older, and he becomes depressed. After having achieved everything he had set out to do.... he was downtrodden.... he had nothing but the gifts given to him by his mother's family.