While I support the reccommendations of others that you go see a specialist, I have to point out that there's a possibility that the doctors you've seen might be correct. They are, after all, doctors. The fact that they're not telling you what you want to hear does not make them wrong.
It's your body and your health, and it's your responsibility to take whatever action you feel is needed to take care of it. If you persist long enough, you'll find a doctor who is willing to take your money and "cure" you. Please at least be willing to listen to the other side of the story.