How awful for you! That must just be so confusing and terrible feeling. And, with no help after all of the tests and doctors! Frankly, I think the only thing left to do is pray! You may have done this already but just pray more. God is there for you. He made you and he can fix you. I had severe migraines for two years and it took two years of me and my mom continually praying before God answered our prayers and the migraines stopped completely! Even if you don't believe in God and Jesus, at this point what have you got to lose and everything to gain? I will say a prayer for you also.
Best wishes,
PML