What Causes Chronic Coughing And Wheezing With Shortness Of Breath?

I have been experiencing symptoms that have been worsening over a long period of time having to do with my chest and my breathing. These symptoms include coughing and wheezing, mucus, shortness of breath (worsening with activity, but even occurs with little to no exertion), and occasional sudden, severe chest pains during inhalation. Also, I am 31 years of age, and have been a daily smoker for the past 20 years. Upon taking X-rays, my lungs were inflamed. What is the most likely cause of these symptoms?