Swollen lymph nodes lasting over two years suggest a chronic underlying condition rather than a simple bacterial infection, which is why Zerodol and Oflomac have not worked. You should avoid further self-medication. It is crucial to consult a physician or an ENT specialist immediately for a proper diagnosis. You will likely require blood tests, an ultrasound of the area, and a Fine Needle Aspiration Cytology (FNAC) or lymph node biopsy. This evaluation is necessary to rule out chronic infections (like tuberculosis), autoimmune diseases, or lymphatic disorders, and to guide appropriate, targeted treatment.