Hi Marie, and welcome!!!
I completely relate to what you wrote. My eating disorder began as a result of a traumatic event and the anxiety and depression, but then it developed into it's own thing.
My T and I just talked about this the other day - how the ED is a way to dissociate from the painful feelings, and how it is a 'manifestation' of my internal feelings.
I am also terrified of gaining weight and only feel secure when the number goes down.
My ED has become the main way I cope with everything.

My T says that once I resolve the trauma issues the ED will have less of a hold on me. I can't imagine this happening - can't imagine a time when the ED will ever truly go away.....
I don't really have any good advice insights for you, except to tell you that you are not alone!!

Take care.