HI, thanks for using healthcare magic
Persistent coughing can be related to different possible causes , the most common are post nasal drip
, gastroesophageal reflux disease
Since in addition to the coughing,you are also experiencing nasal congestion
then it is most likely that your symptoms may be related to rhinosinusitis.
This is inflammation of the nasal and sinus passages.
You may want to consider the use of a decongestant, this can be found combined with antihistamines such as clarinase, zytec d or allegra d .
This combination can be used with a topical nasal spray
I hope this helps