The speaker opens with a threat, "I will ruin you," but the poem soon shows it's really a confession. They're warning someone they love that being close to them will hurt. The damage won't come from cruelty, but from who they are: their long words, broken looks, and worst memories sit alongside their loving looks and greatest memories. The repeated pairs of opposites suggest a person who holds both tenderness and pain and can't pull them apart.
The mood is anxious and sorrowful. The speaker insists they don't mean to hurt anyone and says they are trying to fix themselves, yet they seem convinced it won't be enough. The ending is the saddest part: they predict the other person will leave, find happiness, and leave the speaker alone in the ruins. The final irony is that the speaker, who warned of ruining someone else, ends up with the heartache. The simple, repetitive language makes the fear feel raw and unpolished, like a worry the speaker keeps circling back to.