Hi Dear,
Welcome to HCM.
Understanding your concern. As per your query you have symptoms of runny nose and severe 
cough which is due to infection of upper 
respiratory tract and poor immunity of your body.
 Need not to worry. I would suggest you to 
- Avoid use of spicy, sharp oily and fried food substances. 
- You should do warm saline rinses 3-4 times a day.
- You should avoid cold carbonated beverages. 
- Take diet rich in multivitamins. 
- Apply mist humidifiers in room and take throat soothing agents.
- Take combination of antibiotic 
Levofloxacin along with antihistamine such as 
Levocetirizine.
You should visit 
ENT specialist once and get it examined and get X-ray chest done to detect level of infection and treatment can be started accordingly. 
Hope your concern has been resolved.
Get Well Soon.
Best Wishes,
Dr. Harry Maheshwari