Steaming with Apple Cider Vinegar for Sinus Infection

I have been coughing up yellow cold and coughing. This has been going on for some time. I am doing the stream Apple Cider Vinegar but I'm still coughing. I have taken cough medicine, sinus pills, saline spray and I'm still coughing. Does anyone have a solution? Oh, I have been to the doctor and I have done everything he said. Thanks for any info.