@66bookssss I think from what I can see and from a similar ED history, that she is trying to redirect you away from thinking about what the number on the scale or the pair of pants you are buying says. That doesn't mean no self improvement, it means reframing how you measure said improvement.
What I think she is getting at is trying to get you to see that the pain and puffiness issues you are feeling bad about can be addressed without ever focusing on "loosing weight" as a goal. You don't need to loose weight for those problems, you need to gain strength and adjust what you are eating to foods that make you feel better. Weight gain or loss plays nothing into it. You need to make changes on how they improve how you feel in your body, and not how they improve the number on the scale.
This can mean weight loss, but it also might mean weight gain if it turns out you need to build more muscle to support your joints. Neither of those necessarily have to actually change the size and shape you are depending on how you adjust your eating habits.
I don't think your therapist is telling you not to improve, but that the target of improvement is not quite set properly.