That sounds very similar to what my Daughter had last year. She ended up with pneumonia, a lung infection and a sinus infection. She had some very severe back pain and the Dr. sent her for xrays as it seems that with severe coughing you can actually fracture your ribs. As it turns out her lungs were actually bruised. This has been going on far too long hon, I would suggest getting to the Hospital and asking for a chest xray as well as better anti biotics and even a puffer to help open the bronchial tubes. Oh, Tylenol 1 has a small amount of codeine in it, great for helping calm a bad cough.
I hope you feel better soon. HUG