aside from the important statements that
a) chances are that your are eating not enough, and
b) defining "not enough" by counting calories let alone using calculators, will get you no-where but into eating disorders
i have two additional things to add
1) throw away your body fat scale. The figures it is showing you tell you nothing, follow Beth's advice and read my blogpost on how to lose weight healthily and take to the heart what I am writing about using a mearusing tape instead of a scale to measure your progress.
2) reintroduce reasonable amounts of carbs to your diet (for a rational on what is reasonable read this blogpost of mine > http://suppversity.blogspot.com/2011/06/carbohydrate-shortage-in-paleo-land.html - for you, I would start with ~80g NOT from GRAINS, but rather from fruit and higher carb veggies like carrots etc.; if you are working out at least 3x a week go to 100-120g of carbs (and if you /for whatever ideological resaon/ insist on being hardcore paleo, have part of those from tubers)
3) if you insist on going even low(er)-carb (which I have found works mostly only as long as you are pretty chubby, which you are not / don't trust the scale) then PLEASE do me a favor and understand that LOW CARB MEANS HIGH FAT and what you are eating is almost only protein. The result is that your cortisol skyrockets and your liver spills out TONS OF GLYCOGEN it is making from the proteins you ingest so that you do not starve, because you do not give your body enough energy in the forms of FATs or CARBs.
Adel aka Dr. Andro