I am a 33 years old male , I am suffering from congestion and productive cough from last 2 yrs, I have been prescribed many anti allergics by doctors like montere-lc, montere-fx, levocetrezine, but have got no refief, earlier it was just during season change but from last two yrs it has become more chronic. Whole day I have to spit out sputum again and again, so kindly diagnose my problem and suggest me the best medication.