Do you have any idea what caused the loss of appetite and/or slipping in terms of the meal plan?
I think it's quite common for people with an eating disorder to not feel as though they have one. But losing weight in an unhealthy way and/or to an unhealthy extent does indicate having an eating disorder.
Have you ever done a 'pros' and 'cons' list of losing weight? Sometimes that can be helpful in working out where you're at and where to go from here.