If you were seeing results without counting calories, I would say try it a week or two where you eat exactly what you would have if you weren't logging, but log it. Do not pay attention to th guage or if you are "under or over" your calories for the day. Then weigh yourself and see if you've lost weight. Take a look at how many calories you were consuming vs burning and then choose a deficit that brings you close to that number.
When I started Fitbit I was on the -1000 cal deficit and it didn't work very well for me. There were two weeks of almost no weight loss. As soon as I switched to -750 cal deficit I saw results. You might be putting your body into "starvation mode" if you aren't getting enough calories, especially if you don't have much to lose.
