I have resisted responding to your messages for a long time.
I think that you are obsessed about eating and fasting. We have talked about this before....IMO, you are replacing some strong emotion by eating. As far as I can tell from your posts is that you did not have a desirable relationship with a friend. That may be one reason, but you need to examine this for yourself. First thing you can do is to post on "Relationship" forum and ask "Soulfulsurvivor" to give you some pointers.
After that if you can get professional help that would help you for long term. You are young and will rebound from this if you take small steps.
I personally think you should not fast till you solve some of these issues. After you solve your issue of eating you can cleanse your body with all types of cleanses including fasting.
I feel for you. I know you will conquer this issue.