A 28-year-old woman presents with a 6-month history of recurrent episodes characterized by palpitations, sweating, chest tightness, and a sense of impending doom. The episodes occur unexpectedly multiple times per week, last about 10 minutes, and are followed by persistent worry about their recurrence and its implications. Over the past 3 months, she has begun avoiding leaving her apartment alone, taking buses, and visiting crowded malls out of fear of having another episode. These avoidance behaviors significantly limit her daily functioning and social activities. Vital signs, physical examination, and laboratory investigations (including thyroid function tests and ECG) are all within normal limits. Which of the following is the most appropriate initial management for this patient?