For your cold, rhinitis, and headache, you can take paracetamol or ibuprofen to relieve pain. For nasal congestion, a saline nasal spray or a non-drowsy antihistamine like loratadine can help. Since you are already experiencing drowsiness, please avoid sedating medications, get plenty of rest, stay hydrated, and avoid driving. For your cough, warm fluids or a simple cough suppressant like dextromethorphan can provide relief. If your symptoms worsen, or if you develop a high fever or difficulty breathing, please consult a healthcare professional in person for a proper evaluation.