i'm a 41 yr old male, in fairly good shape, no previous health issues, dont smoke, never had asthma. about a month ago i was eating a lot of ice cream (i'm not sure if this is the cause but it's all i can think of) and developed a bad cough. it was a cough where i felt like something wanted/had to come up but only did so a few times and when it did it was yellow. about a week later whenever i would inhale, at the end of the inhale i would feel something, some kind of 'movement' at the bottom of my lungs. this brought on shortness of breath. at this time i started getting slight fevers and cold sweats for a couple of nights so i went to the doctor. he prescribed me some antibiotics (z-pack, 3 days), and said i should get a chest x-ray if it didnt go away. the fevers and cold sweats went away but not the shortness of breath and inhaling 'movement' so i went for the x-ray. the results came back negative. that was a week ago. so i still have the shortness of breath and the 'movement' although both SEEM to have lessened. i'm still coughing up phlegm although not as much (when it does comes up) and it's turned white/milky in color now. my question is is this something serious? is it something that will go away on its own or should i see a lung specialist? any help or insight would be much appreciated. thank you.