How long have you been following the diet? You may be experiencing "carb flu" which is actually an electrolyte imbalance. A Gatorade type sports drink can help a lot. They have low sugar ones. There is a lot of advice.out there on making your own, but I would be careful because of your GD and pregnancy. Don't just go taking vitamins.

It usually passes in a few days once you get your electrolytes balanced. With all this heat, this is my guess.

I've done keto for a long time.