Francis, I was recently in a similar situation - exercising myself into starvation mode. I took a week off from working out, increased my protein levels and like magic 8 lbs fell off in the course of a week. I've actually done this twice. It seems that when I workout heavily, it is not possible for me to eat enough to sustain fat loss. I can build muscle, no problem, but my body refuses to let go of anything.

Finding the right balance between exercise and calories can take some tweaking. It sounds also like your body adjusted very well to very few carbs - something our bodies are very good at (adjusting).

While I am not suggesting you stop exercising I would suggest a break. The stress of working out w/ insufficient nutrients can cause you to stop losing - cortisol swimming around in your body is a nasty thing, it hinders fat loss and muscle growth.

I would look to increasing water intake (aim for 1/2 your body weight a day in ounces) and I would track protein and calories for a few days - just to get a handle on things.

You might also try mixing things up a little - again to defeat the adjustment factor. Do some different cardio a few times a week, make it higher intensity or lower intensity. Lift some weights. Shake things up.

I would also use a few other measures of fat loss in place of the scale (it lies ) . Compare measurements; keep a pair of 'test pants' handy and try them on every few weeks. Look for other signs of progress - usually they will be evident when the scale shows nothing.

HTH
Nat