Take a second opinion from some other neurologist. Get sugars checked. Get a Nerve conduction test also to see if nerves are functioning well.
My wife has been suffering the same symptoms only accompanied with fainting and all scans and tests were normal. she was diagnosed as cluster headache since the headaches are very severe. However there must be another reason. we are currently treating the symptoms but we do not know the cause Good luck with you and please let me know if the nerve condution test shows anything to track