A lot of cough mixtures actually make you cough. The "expectorants" are meant to help you cough up the cr@p in your lungs. Just go see a doctor and get properly sorted. Don't wait until you have pneumonia.
Go to google images. Search for the word "coughing". It may not assist, but it does look like pictures of random people giving the invisible man a BJ. May as well cough and laugh!
I have been to the doctor and she just gave me a cough mixture called sopholex (not too sure of spelling) and that didn't work, I grabbed some good old benylin and i'll give it a try