5 years of Constant fog, fatigue daytime drowsiness and vision problems. Please help!!!

For the last 5 years I have been suffering with an unknown illness. I feel as I am in a constant fog and pressure feeling mild headache in my head all the time. I have really bad spells once every week where I can remember names of people I work with everyday, a tingly feeling all over a pressure feeling above my eyes and across the bridge of my nose and sleepy feeling. It is almost as my blood Sugar drops. My vision is hard to describe but is as my eyes are slow to refocus. My eyes are bloodshot a lot, feel puffy, lots of floaters, watery and are very sensitive to sunlight. My ears feel full sometimes. I don't have any pain or body aches anywhere except a pain in my ears sometimes. I have been on depresants for a while and they seem to help with the stress and have reduced the frequency of attacks a little. I have had blood panels ran, allergy tests, been examined by the head neurologist at a teaching college and examined by a two ENT doctors, had an MRI and a CAT. Everyone says its anxiety related cause they can't find anything, but I know it is something else. I have found out that if I fast on jucies for a day, I almost feel normal for a few days. I wondered if this could be food related? I have tried b12 supplements with no avail. Does anyone have any ideas?