What was the weight loss goal you entered? If you are trying to loose more that 1 or 2 pounds per week, the calculator will give you an unreasonable low amount of calories that you can eat in a day.
If I read your post correctly, it looks like you are trying to lose about 5 lbs in a week. Thus the 964 calorie restriction. 1 pound is about 3500 calories. If that is the case and your daily requirement is about 2700 calories, then the calculator is saying, yes, you get to only eat aobut 758 calories a day, which is really not enough to keep you going.
You might want to do back and redo the calcs, exploring different weight loss options.
2.5 years, 45 pounds later... 128ish pounds