I wanted to pop in and say welcome back to HW. I am so sorry to read about the partial dx of Addisons Disease. I did a check on Google for it, then went into the Mayo site and read briefly about it. From what I understand its a problem with the adrenal glands not producing the hormones sufficiently. If you have not read the info at the Mayo site I recommend that you do, very informative without a whole lot of gibberish only a dr can understand. From what I read tho its treatable and its considered an autoimmune disease.
With your sister having this disease at least you have someone close that can give you some first hand info and that will serve you very well I am sure. I just hope that you have a very good dr and he/she can get you on the correct medications which appears to be the hormones that the adrenal produce that you are deficient in. It also talked briefly about sometimes the pituitary(?) gland being involved. Its never good to be stricken with any illness or disease, however, if there is treatment available there is a little light at the end of the tunnel.
Knowledge is your best weapon and the more you can learn and get accurate info the better off you will be for sure. I am sure you are terrified, just don't overload your brain trying to learn everything you can overnight. Stick to the reputable medical sites online.
Please keep us posted here on how thnga are progressing. Gentle hugs coming your way.....Susie