archus
Many of us have advised you to seek professional help a few times, you are obsessed to get to 78 or 82 lbs, and bad news is you are already extremly underweight.
Please talk to a friend, loved one, family member about what you are planning to do, seriously you need to talk to someone. You are not fat at all, I am sure you look beautiful just the way you are, so please believe that and stop hurting yourself.
First step is to realize that you are harming yourself and accept the responsibility. You may have been hurt by someone in your past. If so, you need to forgive that person, forgive yourself and move on.
If you do not have anyone to talk to, please go to Emotional help forum, Relationship forum and find a poster named "Soulful Survivor". SS will help you to get to a right path.
Peace.
Archus