Teal Sister - it sounds as though you have endured enough appointments, tests and getting poked and probed without any answers.
Here is my suggestion. When you absolutely cannot stand the pain another minute, hop in your car and drive to your nearest Emergency Room. I'm told migraines account for the greatest number of ER visits, so why should you not be one of them? The good thing about going to the ER is 1. they will medicate the migraine and you will experience quick relief. 2. If you seem like you are in enough pain and you tell them how long these headaches have been going on with no relief, they may bring in a neurologist on call (I recommend you go to the ER Monday - Friday during normal business hours). The neurologist can prescribe for you a prescription med that will hopefully help, and ask you to follow up with him/her. 3. If any additional tests are needed, they will conduct them then and there. AGain, it's imperative that the staff will take their cues from you and how disabled you appear to be.
I wouldn't tolerate the shabby way you've been treated a minute longer. Sometimes the ER is the fastest way to get the help you haven't been able to receive through "the system" as you tried to follow the rules. Good luck.