Welcome to Gaia! ::

Because ever since Korra was a little girl she is the Avatar and that the balance of the world relies on her. Her entire life has been built up for that very purpose. And, every single antagonist she has faced in this series has threatened that purpose. Each one has attempted to end her life and the cycle itself and Zaheer came very close. And, now she is there trying to pick herself up from that traumatizing event feeling like the world itself is trying to say that the Avatar is no longer needed. The harmonic convergence has brought the human and spirit world together again, and as Tenzin says he and the airbenders will keep the peace as she recovers. All of this is making her question her very existence and who she really is as a person once you take away everything that makes her the Avatar, and it terrifies her.