Can you tell us if you are currently being treated by a Gynecologist for your amenorrhea?
You mentioned that you had an eating disorder as a teenager, and I'm wondering how long ago this was? Women who struggle with an eating disorder can recover from this disease, but it is a life-long process. Do you feel you are in recovery from your eating disorder, and have you experience relapses (as most women do)?
What is your current weight/height, as even if you are in complete recovery from your previous eating disorder, you still may be under weight...a primary cause of amenorrhea (lack of periods).