Suggest Treatment For Strep Throat Leading To Cough And Swollen Lymph Nodes

I went to the doctor 5 weeks ago and they said I had strep. After 3 weeks of not getting better I went back and they gave me different antibiotics. I am still coughing and have very swollen lymph nodes all along my neck. More importantly, I have one specific gland that is noticley bigger than the rest that bulges out. Should I be concerned?