thanks for your question i completely understand your problem if you are an ex smoker then u might be suffering from copd for which u r taking inhalers and yes there is a possibility that there might be a lung mass developing inside causing pain but this not the only reason there are other reasons also like pleural effusion, or if u had pulmonary tb earlier leading to fibrosis that can also cause pain in the region no need to panic consult a pulmonologist , he will request for a chest xray or ct if needed and then all the possible causes can be easily ruled out .dont delay any disease if diagnosed in early stage can be treated to an extent thanks/ regards feel free to ask more queries may god bless you with good health