For your hypothyroidism, do you know if it's mild or full blown? If it's mild, it is reversible and it would take time for your body to reach homeostasis. You can do some research and look up additional information for hypothyroidism caused by anorexia. The one thing I found throughout other forums is this quote from the NewYork Times:
"People with eating disorders are at risk for hypothyroidism. In these patients, however, reduced thyroid function may be an adaptation to malnutrition and, therefore, some experts think that only the eating disorder should be treated, not hypothyroidism." It would depend on the degree of how much your thyroid is affected, but the first thing your primary care physician is that they may treat your anorexia. I had anorexia when I was a teenager and it was very hard to deal with. I think the thing that broke me from it was antipsychotics since they make me always hungry. I'm normal weight now and I go to the gym to be fit so my meds don't change my weight.