Dear, the reason you feel ill is because you're starving yourself. You need to stop before if become severe psychological problem that you lose control of
You need to research more about the the body, the purpose of food and nutrition to your body, and what constitutes a healthy diet. Yiu have to eat healthy and have some activity.
You can't live a life of one light meal a day. It's not sustainable, your body will feel deprived, you'll have hormonal cravings as a response that will cause you to binge. You'll become weak, your hair will become brittle. You'll lose your confidence and never feel satisfied, no matter how much you lose. This is a bad place.
The point for us all to lose weight and change our habits so we never become fat again and enjoy the use of our healthy bodies
Do some research, look up some of the success stories of the women on this forum, some who have lost HUNDREDS of pounds while eating SIX meals a day. They are truly inspiring!