thank you for your question....
there are a few questions i need to ask-
what is your age?
do you have any history of allergy?
is there much environmental pollution?
do you experience any respiratory distress? mainly following exertion?
now from the history you provided, it looks like some allergic condition which has flared up recently owing to some environmental change or something....
however there are other possibilities which need to be ruled out...
as of now you can do the following-
chest xray pa view
allergy profile
tab 
allegra 120 - once daily before sleep for 10 days
cough syrup twice daily for 
dry cough for 7 days 
avoid exertion and pollution
get a 
sputum culture done
you can consult me back with your reports..
hope this was useful...