I had lung radiation at the beginning of the year and in January contracted pneumonitis as a result. It created some serious lung inflammation, and it's taken this long - and a lot of prednisone - for my lungs to finally heal and go back to what they were originally. I could barely even make it up one flight of stairs, but my lungs are now back to what they used to be.. I was convinced I had severe COPD (I was told in 2019 I had a mild case of it), but was informed by a pulmonologist who went over my CT's with me that lung inflammation and COPD are two different things. Before you jump to conclusions, I recommend taking some time to allow your lungs to heal and see if the inflammation goes away.