Your goals seem fine. 10lbs by mid March is a little over a pound a week and with 50 to go, very achievable.
Unfortunately, not every individual body reacts to the maths as exactly as every other body. The calculations are averages and may not work for all.
I agree that you might need to eat more.
The simplest way to get your system to show that is to change your goal date and push it out so you're losing more slowly. This will increase your range. The reason why to do it this way rather than manually increase it, is that it'll calculate carbs/fat/protein for you, so you don't have to. :)
Deb, in New Zealand