Hello, with your symptoms and history, you definitely should be taken seriously. What was the result of your hba1c? Do you know that non-diabetics have results of < 5.0?
You need some further testing, and you need to be getting a blood sugar meter so you can measure the impact of what you eat and then use that information to plan your meals.
The best way of eating for people with diabetes or pre-diabetes, or even at risk for diabetes is low carb, moderate protein and higher fat (enough healthy fats to get the calories you need). This can be similar to the paleo eating plan, or just avoiding sweets, sugars, most grains etc.
Yes find a new md that will take YOUR health seriously