Here, a speaker is caught in a quarrel with themselves after a relationship has ended. The heart and the head are treated like two people sharing one body, and they want opposite things. The heart insists it is right and longs for the other person. The head knows better, and what it wants is for that person to be gone. Even the word "yearns" is shared between them, which shows how the same strong feeling can pull in two directions at once.
The short, balanced lines make the argument feel like a back-and-forth, each side answering the other. Then the last stanza breaks the pattern. The speaker decides to forget, and the head wins, but the victory is hollow: "My head's free, my heart can't breathe." Freedom for one part means suffocation for the other. The mood is sad and weary, with a quiet honesty. Nothing is resolved neatly, and the speaker seems to understand that choosing reason doesn't make the ache stop.