Cough that won’t go away, doctor prescribed decongestants, antibiotics and steroids, need second opinion?

Hi, I’m a 26 years old that have a productive cough that won’t go away.

When it first started the doctor prescribed me antihistamines, after a month of those, I felt worse and another doctor prescribed decongestants, antibiotics and steroids. Those helped for a little, but once I finished the cure, the cough came back and another doctor gave me antihistamines and nasal spray which didn’t help at all,
I don’t know what to do anymore.
In attachment there is a Xray I did when it first started.