I ate a few donuts this morning. after i felt shaky, dizzy, weak, nervous, tired. could i have had a hypoglycemia/diabetes?

No: In my 35 years of practice, I have never seen a case of reactive hypoglycemia. The disorder doesn't exist, if you're overweight the symptoms are a natural response to your glucose level returning to normal. A glucose tolerance test (if you've had one) is not and never will be a valid diagnostic test for hypoglycemia. Don't waste your money o GTT or any fad diets of treatments. Lose wt if heavy.