140 carbs in one cookie? Is that even possible?

Whatever, if you read back through a few pages of this forum you will see many posts with similar concerns about how fast or how low blood sugar numbers should come down. Many examples to show that ups and downs are "normal" You can also check some of the doctor examples of clinic experience. Here's Dr. Westman's, available to all as a 30 minute talk: https://www.dietdoctor.com/lchf-dia...dr-eric-westman

Hang in there with a very low carb plan, minus the cookie, and you will see results.