The speaker is worn out by heartbreak. The poem turns falling in love into a literal fall: she climbs to "the vault of heaven," breathes in, and lets go, again and again, until she lands somewhere painful. Her question, "Why do I keep falling for the wrong people?", feels like something she assumes everyone asks sooner or later.
What follows is a kind of defiance. She decides there are no soulmates and no perfect match waiting for her, and she refuses to be "fooled" by romantic ballads. Yet the tone isn't really cold. The tears, the repeated falling, and the odd image of someone waiting for her to "break their heart" show how hurt she is beneath the toughness.
The ending is the saddest part. After believing in love for so long, she realizes she has come to hate "the most wonderful feeling in the world." The mood is raw, tired, and disillusioned, with grief hiding inside her cynicism.