Also, since you underwent radiation, this could be a side effewct of that.
My husband was radiated in the chest
area, and has since had much congestion
to teh point of shortness of breath. His cancer is in remission, but teh radiation has effected his heart a bit, and teh mitral valve is leaking. After being treated for bronchitis twice, seeing his oncologist, and cardiologist, nothing showed up except for some fluid in teh lungs.