As other posters said, try to get many diagnosis from different doctors.
And try to get unbiased opinions from them - don't provoke the results from one doctor to an other.
I don't have much experience with doctors luckily, thus I am talking theoritically.
In an other aspect - house renovation - this works. I try to take opinions from many craftmen on what to do, how to do it, I detect then what the market price is, etc.
The idea is to create some liquidity of professional opinions around your problem.
I wish you trully good luck with this!