I don't understand!

Oh I am! I'm eating no more than 1500 calories a day even though I got 1800 cals on IIFYM with no exercise. According to IIFYM, if I exercise daily, I should eat 2357 cals a day. Isn't that a bit excessive? Or should I eat this much?

You keep saying 1500 and people keep telling you its not enough. Stop thinking Calories = Teh Devil. Calories are fuel to run, repair and maintain your body. If you are working out, as you are, you need more calories to keep your body nourished and running well. If you are not eating enough to keep your body going, your body is going to be forced to pull nutrients from itself and/or restrict what nutrients go where. Your body will not repair as efficiently, you will feel sore and tired more often and your workouts will suffer. When your workouts suffer, you are not going to make reliable progress. You also potentially run the risk of injuring yourself. Your calories per day are supposed to be a goal, not a line in the sand you do your best to avoid getting near.

For a point of comparison I'm a female, 36yo, 5'2", pretty much sedentary outside of my workouts with ~20lbs to go, yet I still require ~1880 to lose using a 15% reduction. You should most certainly be above that. I'd suggest reading the Sexypants thread and learning how to calculate your caloric and workout needs, how to assess them and when to reassess them.

http://www.myfitnesspal.com/topics/show/1080242-a-guide-to-get-you-started-on-your-path-to-sexypants

As to ketosis and the workout regiment you have, I'll pass that for someone else.