Hello.
Fatigue, shortness of breath, and a persistent cough are direct symptoms of chest allergies resulting from smoking, which directly affects the lungs. Therefore, I advise you to stop smoking immediately to regain your health and use bronchodilators and expectorants.
Regarding the medications you mentioned, they are helpful for those suffering from shortness of breath and coughs, but a medication for chest allergies can be added. However, the dosages should be prescribed by a pulmonologist because they vary from case to case based on a direct examination by the doctor.
Wishing you a speedy recovery.