Have you tested your blood sugars right after eating (like 30min after) to see if you are experiencing high blood sugars? I used to get that feeling from eating carbs too, especially something like a bagel. This could be the beginning of pre-diabetes especially w/ the reactive hypoglycemia which I also used to have before getting pre-diabetes.
The good thing is eating this way will stop all that from happening to you as long as you stick to the diet. It's that simple. I don't know if it will go away after a while and after you've lost all the weight. I'm not there yet either.