The speaker can't stop thinking about someone. Thoughts of this person crowd their head, and the small daydreams of a future together are starting to crack. What hurts most is that the speaker's own heart has turned against them. Their mind says to forget this person, while their heart pulls them toward an embrace, and the two sides fight until the speaker feels torn in half.
The poem's shape mirrors that split. Words like "Breaking," "Me," and "Apart" sit alone at the ends of lines, so the sentences themselves seem to come apart as you read. The title does the same job, naming the ache before the poem explains it. The final line, set off by a gap, feels quieter and a little helpless, as if the speaker is admitting the cause is simply their feelings. The mood is raw and anxious, full of longing and exhaustion, the sound of someone who wants relief but can't choose between letting go and holding on.