T can't stop you- you can tell her and still keep on doing whatever you want to. T can, however, help you to realize whether you really do want to go down this path... Telling helps, it really does.

I had an ED, was MA, now I'm normal weight eating OK(ish), food is still one of my coping mechanisms (and not the worst I must admit). I strongly disagree with the permanent damage on your metabolism claim- it was one of my reasons why I felt I couldn't eat like others do- after years and years of restricting I felt (and heard often enough) I destroyed my met forever and therefore must restrict till I die- It turned out that no, I didn't and I can eat normally- it takes a time but given the chance your body will get there (with proper nutrition, exercise and stress reduction). Healing from ED IS possible.