What i make out from your brief is that you are suffering from an obstructive lung disease
that can be because of your hyperreactive airways or because of your smoking
habits. Although u have left smoking still whatever damage the cigarettes had caused cannot be reversed. Another thing that i find missing in your brief is any family history of allergy
. May be you have an allergic diathesis which keeps flaring up with seasonal changes or contact exposure to dust and smoke. Have you ever underwent a lung function test and if not then i think it is something what u should and get back to a pulmonologist for the treatment.