You have a family history of Addison's disease and Celia disease which makes you statistically more likely to develop an autoimmune disorder, than those in the general population, but it does not mean that you will develop one of these problems. The investigation as I understand it has shown a subnormal response to insulin induced hypoglycemia but normal responses to ACTH stimulation. The first question is to find out what your morning level of cortisol was. If it was over 300 nmol/l, the probability of adrenal insufficiency would be low. The next question would be to check and be sure that your blood sugar fell to a low enough level to cause ACTH stimulation (it should go down to about 2.5nmol/l). If there was a low fasting cortisol with a subnormal response to insulin, but the response to ACTH stimulation is normal, your endocrinologist would be looking at a possible pituitary cause for your low cortisol. Since I don't know your whole story, there may be other factors accounting for your symptoms. It is important for you to discuss your concerns with your endocrinologist so you can get her response to your questions.