Hello, 
Chronic cough is commonly caused due to allergy, RTI, asthma, 
bronchitis or 
sinusitis or 
laryngitis, COPD. 
To detect the pathology causing the cough, visit a GP, get physically examined. 
Get swab tests, Sputum test, CBC, 
Urinalysis, X-Ray chest done. Your treatment will depend upon the severity of the pathology detected.
Asthma is triggered by stress which may trigger cough, stay away from anxiety & stress.  Keep yourself well hydrated. Stay on 'Voice rest'. Avoid going outdoors, avoid pollution.
You can take a course of antibiotics, analgesics to feel better. Gargle with a medicated mouth wash or warm saline water 2-3 times a day.
Hope I have answered your query. Let me know if I can assist you further. 
Regards,
Dr. Nupur K, General & Family Physician