My symptoms began in late December of 2011 after a stay in the emergency room. I was having a great deal of pain and was in the emergency room for epididymitis. I was injected with Toradol for pain. The next day after being up for a couple of hours I started to get very dizzy and experience vertigo. I went to the emergency room and the doctor told me I was dehydrated. After a few hours, with the IV in me, I was stable enough to go home.
Over the next month I began to get dizziness and vertigo every night after dinner. This did not go away. I do fasting once a year for 1-3 days. I fasted two days in February of 2012. On the second day of fasting, I experienced the very same symptoms of dizziness and vertigo that I experienced in December of 2011 when I went to the emergency room. I again went to the emergency room and the doctor told me I had a low sodium level. After another few hours with the IV bag in me I felt stable enough to go home.
Since this time I experience dizziness after walking more than a couple of blocks. I cannot walk through the entire mall without getting dizziness. If I try to do fasting, I get the same symptoms of vertigo and dehydration. I had a glucose tolerance test in the summer of 2012 and the results were not extreme, but I may have mild hypoglycemia. The issue is that when I do go to the emergency room for dehydration my blood sugar level has always been normal. I have yet to get any diagnosis for this condition.
My main symptoms are:
1. Dizziness after walking more than a couple of blocks
2. Vertigo and dehydration during fasting
3. General fatigue and exhaustion
Tests I have received
1. ENG (inner ear test for vertigo) no problems with my inner ear were found
2. Abdominal MRI- no problems
3. Cat scan of cranium- no problems
4. Glucose tolerance test- may have hypoglycemia. I had the test in the summer of 2012 and am ordering a copy of the results
5. Blood work showing I do have a deficiency of Vitamin D and B12

My main symptoms are:
1. Dizziness after walking more than a couple of blocks
2. Vertigo and dehydration during fasting
3. General fatigue and exhaustion
Tests I have received
1. ENG (inner ear test for vertigo) no problems with my inner ear were found
2. Abdominal MRI- no problems
3. Cat scan of cranium- no problems
4. Glucose tolerance test- may have hypoglycemia. I had the test in the summer of 2012 and am ordering a copy of the results
5. Blood work showing I do have a deficiency of Vitamin D and B12

What those tell me, considering what you posted about the tests, is that you should take care of your vitamin deficiencies and see what happens. Over the counter supplements can help.

There is no way we can diagnose or even guess at what is going on, even considering the amount of information that you posted. I would try a second opinion but make sure you're consuming everything you need to to be healthy. Including the vitamin supplements.

Its hard for me to get all the nutrition I need because I have multiple food allergies. I have tried supplements for Vit D. and B12. Taking these supplements tends to get slowed down because my system is very sensitive and I get side effects even from these mild supplements.
What I really need is a diagnosis.

Then you need to go to a doctor. No one here is going to diagnose you. If you aren't happy with the answers your current doctor is giving you then go to another one and another one until you're satisfied that nothing is wrong or your on the right track for a solution.

There is NO way you can give us enough information to diagnose, nor does anyone here have enough knowledge or experience to properly diagnose.

You could be anaemic. A vitamin B12 deficiency could lead to pernicious anaemia. Your symptoms do match some of the symptoms of anaemia. Maybe you should try look into that. Vitamin B12 plays a role in the formation of normal red blood cells.

Hope you find the problem and a solution so you can get back to fasting comfortably :)...

You might need to take the supplements by injection if you can't orally. Some of the reasons for B12 and other vitamin deficiencies include difficulty absorbing the vitamin in the digestive system, this could be caused by a genetic mutation or an auto immune response to part of the digestive system.

Again, Hope you find the problem and a solution so you can get back to fasting comfortably...