Not enough calories for diet? (see details)?

I am doing a strict calorie diet because last time I did it I lost 25 pounds. What your suppose to do is start around 2 thousand calories and exercise during the week. When you notice the weight not coming off anymore you subtract 200 calories from your daily intake. And then when your not losing again you subtract 200 more, and so forth. Any way I was coming up with some meal plans and the highest I got my calorie intake per day to be was around 1200-1300 calories ( I am preparing some really healthy low calorie meals). What I was wondering is if I should add some more calories to my daily intake (maybe add more snacks, add more food?) so later on I can subtract because at this point it is going to be hard to subtract seeing as how I am only eating 1300 calories a day. Or will I ever hit a plateau where I will have to subtract from the 1300. Maybe I will keep losing weight sticking to 1300 calories forever! I need help! Thanks.