A 28-year-old man presents with severe sore throat, dysphagia, and fever (39.2°C) for 3 days. On examination, he has bilateral tonsillar enlargement with exudate, cervical lymphadenopathy, and trismus. Intraoral examination reveals the soft palate pushed medially on the right side with bulging of the lateral pharyngeal wall. He is drooling and has a 'hot potato' voice. What is the most appropriate immediate next step in management?