For a few months now I've had excess phlegm in my throat, and I very occasionally cough. I did have an issue with post nasal drip for a few years that caused my nose to itch like crazy, but it eventually cleared up. But sometimes I'm slightly out of breath, not panting or anything, and just always feeling and swallowing phlegm in my throat, so now I've convinced myself I have pulmonary fibrosis. Idk what to do and I'm so terrified