I am not sure what test you are doing, - can you give more details?
It can be a bit of a shock to the system to suddenly abstain from carbs - particularly if concentrating on sugars, and the results can be unpleasant if your brain is used to high glucose levels. Maybe take things a little easier to allow time for adjustment.
I ate low carb whenever I could get away with it for a long time before being diagnosed with type 2 and always felt far better eating Atkins style than on a high carb low fat 'healthy' diet.