A 27-yeаr-оld femаle presents viа telehealth repоrting difficulty maintaining emplоyment, impulsive spending, and “mood swings.” She describes rapid shifts in mood that occur multiple times per day, typically following conflicts with others. She reports a history of unstable relationships, chronic feelings of emptiness, and episodes of self-harm. She recalls being an average student with no significant behavioral issues in childhood. She reports occasional periods of increased productivity lasting several hours but denies decreased need for sleep or sustained elevated mood. Which is the MOST accurate diagnosis?