I'm so sorry you have been in so much pain and for so long.
Have you had an IV of a narcotic to try to stop this pain?
Have you tried Topamax as a preventative medication? People have had fairly good luck taking this medication as a daily preventative. Sometimes Topamax along with a second daily med makes a big difference.
It's possible that there are a variety of sources for your headache and you will want to tackle each one. But until then, Topamax might provide the best overall relief.