I have a low-calorie diet plan, is this a good idea?

This has bad idea written all over it. You should probably already be seeking treatment for eating disorders, because if you almost slipped into it once, it will probably happen again. If you want to lose weight, do it the healthy way. Consume about 500 less calories a day than are needed to maintain weight (they can tell you how much this will be at a drs office or gym), and exercise for about 30 min to an hour 3-5 days a week.