A 28-year-old woman presents to your clinic with a 6-month history of recurrent, unexpected episodes of intense fear accompanied by palpitations, sweating, trembling, chest discomfort, and a sensation of choking. These episodes peak within 10 minutes and resolve spontaneously. She describes persistent worry about having additional attacks and changes her behavior to avoid situations where escape might be difficult, reporting that she rarely leaves home without her husband. Physical examination and routine laboratory studies, including thyroid function tests and ECG, are normal. Which of the following is the most appropriate initial management for this patient?