It sounds like your pendulum has swung too far the other way. You have to remember, this is not an all or nothing journey. You don't have to be so strict on your calories, in fact you're being way too strict! It's not sustainable, it's not healthy, you can actually slow down or stall your weight loss by eating too little, and it's much more punishing than need be.
I suggest you sit down and plan what you are going to eat for the day and make sure ahead of time that you will get enough calories. I would try to stay away from ad libbing your menu. That where some people get in trouble. If you have no plan for the day, then your mind wanders to all sorts of things you could eat. If it's planned out by you in advance, it's easier to resist the impulse eating.