What Is Causing Discomfort In My Head At This Time?

Hi, I have lightheadedness/off balance since March, with a mild episode of start off dizzy in March. All the following tests came back normal: MRI, MRA brain, cbc, metabolic panel, thyroid, adrenal, echocardiogram, holter moniter, ear testing which the hearing, and first part of rotation chair were good. Neurological exam good. I had a ear rotation done too I have taken only Naprelan for arthritis for the past 12 years. any suggestions as to what may be causing this or if I need addtional testing. No fainting. Thanks Pam