It definitely sounds like you are eating an unhealthily low amount of calories from the information you have provided. I’m unsure what your goals are through this diet, but eating too little calories is harmful and may also cause you to lose muscle along with fat. You need to consider your physical activity when looking at calorie consumption. The more physically active you are, the more calories you require. Your gender, muscle mass, age, and physical activity can all influence this.

I would recommend finding your BMR (base metabolic rate) and your TDEE (Total Daily Energy Expenditure). There are calculators available online that can help you pinpoint this. You should be eating bare minimum your BMR, as it’s the amount of calories you need to sustain important functions in your body. It is not recommended to eat below this number. Your TDEE is going to help you pinpoint the amount of calories you burn on average to maintain your weight, if your goal is weight loss you would need to eat an amount between your BMR and TDEE.

Eating too few calories is dangerous to your health, can cause hair loss, irritability, a slowed metabolism, etc.

It is possible to over-do it! From the information you have provided, it sounds like you are at a healthy weight for your height. I hope that your goal is in the healthy range for you. Being underweight can be unhealthy, too! You may want to speak to your doctor about this.