Am I eating enough calories?

That kind of depends. My nutrition textbook recommends eating 500 less calories than you use each day. Your weight, height, age, and metabolism are used to calculate that, along with any exercise that you do. As far as I can tell, the calculator for this site is accurate- so if you put in all your stats and tell them you don't want to lose any weight, that's how many calories you use a day. It's possible if you're short, thin, and spend most of the day sitting that you do only burn 1700 calories a day, but it's unlikely.

1200 calories is the absolute very least you should be eating, and is actually considered by my textbook to be a starvation diet. You have to be really careful with a diet that meager, especially if you aren't getting enough carbs, because your body might start producing ketones, which can build up inside your body and kill you. Your body might also start eating your lean muscle mass. As you probably know, muscle mass burns calories just by existing, so you really want muscles if you're trying to lose weight.

Also, remember to put your health first. Losing weight quickly often fails to address the underlying cause of the problem, and often results in gaining it right back again. You might think to yourself "that's no big deal, I can just lose it again." There are many studies that show this yo-yoing is bad for your health. It results in more weight being carried around the belly and a higher risk for many chronic diseases, along with self-esteem issues. I would urge you to concentrate on developing a healthy lifestyle that keeps you fit, trim, and happy.

While it's possible to lose weight faster, a pound a week is generally accepted as the fastest a slightly overweight person can lose pure fat. If you're losing weight faster, odds are there's some muscle, minerals, and water being lost too.