The speaker is walking away from a relationship that ended in hurt, and "Until" is the word that holds the whole poem together. Every line sets a limit: love lasts until it turns cold, caring lasts until the trust is gone, crying lasts until the eyes run dry. Each feeling is spent completely, so the speaker has nothing left to give.
The repeated chorus is the heart of it. The speaker wants to be "gone," hidden in the shade and behind a song, unseen until they can forget the other person's name. The "( i hope )" in brackets sounds quietly honest. The speaker isn't sure forgetting is possible. Near the end they ask whether this pain was all the other person ever had for them, and admit that healing is something they only tell themselves. The mood is tired, bitter and sad, with a small, uncertain wish to feel glad about leaving.