Lexie get checked for Mycoplasma pnemonia with a blood test. Symptoms include a nonproductive cough, heavieness in chest, sometimes a feeling of one or both sides of the neck as if something feel stuck, fatigue. This is a difficult bug to get rid of if it has lodged itself in your lungs. It is an organism somewhere between a varius or a bateria. Make sure your docotr send your blood to a lab that specializes in Mycoplasma testing. They are difficult to detect. Since there are not a straight bacterium only certian antibiotics work on them. The antibiotics stop the creation of new Mycoplasmas but it does not kill the current ones in your body. If you take a short regimin of antibiotics it will come right back. If you end up having this bug let me know. I'll give you more info.
You might have Asthma or Bronchitis