Well, she feels destined to be the first woman president. She has dreamed of and planned for this her entire life. She is seeing her dreams vanish. She can’t drop out because her whole reason for being will vanish if she doesn’t run for president.
So in spite of her being able to leave politics and enjoy the cushy life with the money from the foundation, she can’t do that and fulfill what she sees as her destiny to become president.
I can easily visualize her offing herself.
Her fallback position is to spend the rest of her life skindiving in the Caribbean which most people would find to be paradise but for Hillary would still be hell.