when i was in holland (amsterdam)...i smoked non stop...one thing that happened to me was that 1 morning when i woke up like i felt like my lungs would kind of stop worrking, and that my stomach would come up to my throat and i wouldnt be able to breathe....it wouldnt be constantly...but every once in a while i would feel this horrible sensation of having to feel like im choking and breathe in very deeply to make it go away. My uncle is a huge pothead and he told me to take alca selser (spelling?).....and it went away immediately. Try that, it may not be your lungs...but if your sure it is....i think it will go away....