I been sick for three weeks now. It started as a regular cold with some nasal congestion and coughing. I had some fever. but the sneezing went away and I just been coughing a lot. sometimes I cant stop coughing for a while. It can be a dry cough then turns into a mucus looking thing coughing up. I have been getting chill, vomit, and diarrhea. Its getting really painfull to cough and I been really weak and tired. what can it be?