A woman told me that her boyfriend was told that Addison's Disease is a genetic disease and he would have it all his life.
Maybe and maybe not. The adrenal glands can become damaged in many ways -- hemorrhage from a car accident, cancer, tumors, tuberculous, HIV, virus damage, other diseases, genetically weak adrenal glands, high doses of cortisone used to treat other conditions, failure of the Pituitary glad to produce the hormone necessary to stimulates your adrenal glands to function, your immune system attacking your adrenal glands, and excessive prolonged stress of any type. (see https://www.addisons.org.uk/info/manual/causes.pdf )
Whether or not your adrenal glands heal, removing as much stress from your life as possible will help you feel better. It will also probably help your body cope better with your disease, decrease the possibility of other complications, and increase your quality of life.
In my case, I seem to have had a lot of stress caused by low oxygen levels (chronic bronchitis and a heart murmur), several injuries, allergies, chemical sensitivities, and unresolved emotional issues. As I worked to control or reduce each problem, my adrenal glands began to heal. My adrenal glands did not produce any cortisone for years and now I able to function without any medication at all.