I echo the sentiment that you are not eating enough. I'm an obsessive calorie counter, however while doing this, I refuse to count calories. I *know* that I was, even while counting calories eating way way below my BMR (eating about 1000-1200 a day, if I went on a "binge" it would be closer to 1800 a day).
So, I've stopped counting, and just eat foods that are acceptable. I've also noticed that there are some days when I have such an awesome breakfast, that I skip lunch, or even dinner!
I'm trying to eat intuitively, I have to ask myself through dinner, am I full, can I save this yummy halibut for lunch or a snack?
I think that when I start to obsess about calories, I feel deprived and that leads to diving off the wagon. I have food to eat, if I'm actually HUNGARY, then I'll eat.
Rough start due to major carb WD.
MWF: 1 hour run/walk, 1.5 hours in the gym - upper/lower and core
Sat/Sun=Yard/house work, chasing kids, playing
Family walk every night instead of everyone vegging in front of the TV
Personal trainer to build muscle mass & to help meet goals