I had a cold, sore throat, runny nose, headache & a cough. All my symptoms went away except for the cough. Now my back & chest are very sore & I m still coughing up mucous. I also have a head ache & fever. What medication should I take? I m an 18 year old Male, 5 9 , 145lbs and I do not take any meds daily. I m not allergic to anything. Thank you