Sweetie, I don't mean to worry you, but I'd feel a whole lot better if you talked to a doc. Maybe a new doc who takes you seriously? Shortness of breath seems normal for someone who's newly riding, and a burning in the lungs from breathing hard. Takes time for the body to adjust to the new demands. Is your chest pain beyond those temporary sensations? I'm not a doctor or a nurse, but we just met you and we want to keep you!