1200 calories is not enough calories to sustain an adult woman if you are exercising for a couple of hours a day. Not knowing your current weight or height, let's say you burn 1000 calories in two hours. If you eat 1200 calories for the day, that means you're only netting 200 calories ! that's not enough.
Eating too little and exercising too much can hinder your weight loss. Why ? your forcing your body to decide which is more important. Having calories to do your workouts or having calories (energy) to your vital organs working. I can assure you that your body doesn't care if you're trying to lose weight. All your body cares about is making sure you have enough calories to keep your heart/lungs working properly.
So, don't short your body the calories it needs to be healthy. I know this is going to sound strange, but a person needs to eat in order to lose weight.
Also, if you lost two pounds overnight, that was from water retention. I can gain or lose as much as 3-4 pounds in a day because of a shift in my water weight.
don't tie your emotions to the scale. Instead focus on the healthier aspects of engaging in a healthy lifestyle. Eating right, not eating less will help you achieve your goal.