SEOUL, South Korea — As the protests against her have grown larger, louder and closer, and her career, reputation and presidency march inexorably toward an impeachment vote on Friday, President Park Geun-hye has kept mostly hidden from public view, gripped by self-pity and despair, and largely alone.

Cloistered in the presidential Blue House, which in a twist of fate befitting a Greek tragedy is also her childhood home, she has had few visitors, aides said.

At 64, she is not married and has no children. Her brother and sister have been estranged from her for years. Her three most trusted aides have been fired over the corruption and influence-peddling scandal that now threatens to undo her presidency. One has been jailed. Ms. Park’s closest friend and confidante, Choi Soon-sil, is also in jail.

Ms. Park has stopped attending cabinet and presidential staff meetings. She has been dejected, she said in one public apology, losing “countless nights” of sleep and at times regretting ever becoming president.