It`s clear from your description that you are suffering from allergy
ie asthma. However you need to undergo a xray chest (which you have alredy got done ) and a spirometry
ie PFT. There after you need to start taking inhaler medicines like asthalin
. You should also take Montair LC. Do some deep breathing exercises, avoid smoke, dust, cold blast, cold drinks and artificially flavoured and coloured food.