You said that it feel like this is the only to gain control. But it's not really gaining control. It may feel like control now, but eventually it'll get to the point where you are no longer in control. I've been struggling with eating issues for over six years; it's not real control. It's the illusion of control.
Restricting and purging are not the ways to lose weight. You have to eat healthy and exercise to lose weight, and you should only do so after talking to your doctor. Your doctor can tell you whether you need to lose weight, and they can help you making a healthy plan to do so.
You might want to think about talking to a teacher, counselor, or friend about this.For one, this is very dangerous, and letting them help you would be best. Secondly, you don't have to do this alone. You are not alone it this, many people here have gone through, or are going through, a similar situation to yours. Don't be afraid to reach out to someone, and please don't do this on your own. It's so much harder if you try to do it alone.
If you nee to talk, feel free to
pm me.Stay strong.