Number one, you're not even halfway through this Whole30, it is way too early to know whether you will ultimately lose weight or not.
Number two, a healthy amount of weight to lose for sustainable weight loss is considered around 1-2 pounds per week. You may have lost more on your first Whole30, but big changes often result in more weight loss than normal. You've done this before, it's not new anymore, and you may not lose as much. You might want to rethink your timeline for losing those 10 pounds.
Finally, why not try something different than the typical diet? Do you believe that Whole30 is making you healthier? If you do, why not just keep eating close to Whole30 and getting healthier, focus on things like exercise, sleep, and stress -- which all also play a huge role in health and weight -- and let the weight loss happen as it happens? If you're getting healthier, your weight will adjust itself accordingly. People always assume that losing weight=getting healthier, and that can be true, but what we're asking you to do is look at it from the other direction. Focus on getting healthy. If you are healthy, your weight will adjust to a point that reflects your health. We can't guarantee that the number your body settles on will match the number you currently have in your mind as your ideal, but if you feel good, and you are active, and you can do all the things you want to do, why does an arbitrary number matter so much?
Personally, I write down anything that went well that day. No cravings? Cool. My kids didn't throw a tantrum? Great. The book is for YOU. For YOU to write about anything that went well that day. Got off work early? That sounds good to me- write it down! Didn't have to explain what the whole30 is, someone just accepted it? Win. Didn't have to think about when your next meal was coming...write it down.
The book is for you to track your progress and how you're doing mentally. The tiniest thing can be positive. Write. It. Down.