I just experienced a crippling pain in my right lung and any attempt to inhale was extremely painful. It went away and now I’m fine. It happens occasionally so I hope that isn’t an issue that I’ll have to spend a ton of money on.
As someone who died of pneumonia caused by a fungal infection in my lungs (I got better). I would recommend a doctor looking into that. My symptoms were a sharp pain in deep inhalation and uncontrollable coughing after exercise. Don’t just stop at the first GP either. GPs are great for entry level diagnosis of common ailments but if you still feel wrong keep pressing. If you feel in any way febrile, if your temperature goes up or down get to ER or A&E.