Change doctors first, Then keep details notes of how you are feeling, what you eat and and how you are feeling for your new doctor. Then maybe they can see a trend of what might be causing the problems. Believe me it works. Kept my husbands very detail blood pressure and now he is seeing a cardiologist getting major problems solved. Detail notes tells a lot - more than just saying this or that.
Good luck - good doctors a hard to find but please remember if one doesn't help you - there really is another down the road that will. Just keep trying and good luck to you.