Tiffany's poem is about watching a relationship fall apart and the self-doubt that follows. The speaker describes coming home to someone who feels like a stranger, then seeing that person's love shift away from her and toward someone else, "less and less" for her, "more and more" for him. At first the speaker seems to reach a kind of understanding, saying she now sees why they "weren't meant to be."
That calm doesn't last. The understanding turns into harsh self-judgment, as she decides she is "meant to be alone," "worthless," and meant to die "alone and depressed." The short, plain lines make these statements feel raw and unguarded. The title's "paradise" feels ironic, since being lost there suggests a place that should be good but isn't.
The mood is sad, numb, and quietly desperate. The final question, "Am I really fine?", is directed at the reader and suggests she isn't, and that she may be hoping someone will notice.