Hi I Have A Tender Swollen Lymph Node On The

Hi
I have a tender swollen lymph node on the left side of my neck this happened the same time as last year I got all kinds of blood tests done and ultrasounds and my ent did an open biopsy and now its back again I don't know what to think besides it could be from allergies I have headaches stuffy nose and I'm very tired and have fluid in my ears what do you think?