I had a razor blade throat last week, which has now porphed into a tickly cough. I coughed for THREE HOURS last night in bed before I finally went to sleep. Today, I can't stop coughing. It's bloody constant, and I am getting a headache and sore chest muscles from it. It feels like I need to cough up phlegm, but nothing is coming up. Tell me what to buy. I am dreading tonight!