First, it starts with your attitude. The fact that you have had eating disorders in the past is probably part of why you are also holding onto this negative attitude now.
Mentally you need to take control. Mastering yourself isn't something that happens over night, but it can be achieved. You need to discover the limits of your own mental and physical ability and aspire to be the best person YOU can be.
Second, MOTIVATION. That's right, red. Motivation, determination, and a helping of discipline. THAT is what will help you to make healthy choices and point you in the right direction.
Don't think for a moment that you won't have to work for your body. But if you really want it, drop that attitude, get motivated, get determined, and do something about it.
Otherwise, you can just keep doing what you've been doing, you'll get what you've always gotten.........