Shortness of breath with nasal blockage.

Hello I am a 34 years old male having on and off shortness of breathing for last 15 years that improves automatically within 2-3 days but not associated with cough. Mostly it hapens while talking to my clients for a long time but it subsides after taking rest for sometime. Whenever I feel shortness of breathing I also feel tired on walking upstairs.but when shortness of breath goes off I live a normal life no problem at all. I have a strong family history of asthma. I did ECG echocardiograpgh thyroid profile chest x ray spirometry R/E blood, lipid profile all are normal. Only IgE level is high293 and x ray nose and PNS shows right maxillary haziness. So what will be the probable diagnosis. Is it asthma or something else? and is it due to the chronic on and off nasal blockage? What should I do? I saw a Pulmonologist and currently taking esiflo 125 BD. SO kindly suggest me what should I do and what might be the probable diagnosis?