Hey, don't feel sad.
On a lighter note, your results doesn't mean you have diabetes. It means that there is lower tolerance to diabetes. A diabetic is determined by a high blood fasting sugar or a 2hr reading of >11.6 mmol/L. The good thing is we now know that eating too sweet is not good for us, which is true for everyone.
Having GDM forced me to reduce my carbs and sugar intake, and it kicked out my sweet tooth and increased my veg intake ridiculously. My nutritionist recommended that every meal, we should have 1/3 carb, 1/3 veg and 1/3 protein. My sweetness level was "reset", and now I find most commercial food to be too sweet. But hey, I couldn't feel any more energetic than ever!
Many people go on in life without knowing that they have lower glucose tolerance and as a result go on to become a diabetic. Now we have a chance to be mindful. Jiayou tog! Cheers.