Dear thanks for the question. Mild cough is common after a flu attack for some duration but in my view you are developing lower respiratory tract infection along with bronchitis (chronic cough, difficult breathing). To my patients with these symptoms I advise chest x ray, blood profile, lung function test (flowmetery) with culture and sensitivity of sputum. I would advise you to visit a lung specialist in your area for conclusive diagnosis and treatment. I hope I have answered your queries. Wish you good health and faster recovery.