The speaker is caught between anger and exhaustion after someone's thoughtless words have deeply hurt them. The opening lines set up the central idea: the other person drops words "so easily," without realizing how heavy they are. For the speaker, those words have real consequences, and they say they are "going insane."
The middle of the poem is about identity. The speaker is still here, but as "a version you killed, / And a version I made", a self damaged by the other person and rebuilt on their own. They want to be seen, asking to be noticed as "perfect," yet every attempt to talk ends with the other person walking out of the room.
The ending turns inward. The speaker is shocked at having ended up "at your beck and call," and the question "How did I stoop so low?" carries shame as much as hurt. The mood is raw, frustrated and pleading, and the title, "Let me go," suggests the speaker wants to break free of this pull.