I'm 25 and having a bit of a scare here. I've been coughing up this black phlegm, dealing with nasal congestion, and feeling breathless, but it gets a bit better after I cough. I havent smoked ever, and I live in an area with clean air, so Im really confused. What could be going on with me? And what kind of medication should I be considering? Also, I'm not experiencing any cough or fever along with it.