Low Cortisol Levels but Normal ACTH Stimulation

I recently went to a highly recommended Endocrinologist due to consistent low levels of cortisol.  I am a 42 year old female and have been fighting a supposed virus for the last 2 1/2 yrs (herpes zoster & possibly another but not clear cut diagnosis). The Endocrinologist tested my blood to find again the cortisol levels low and decided an ACTH Stimulation test was needed.  To my surprise, the nurse reported to me that the ACTH Stimulation Test was normal.  My question to the nurse to take back to the doctor then is why is my cortisol levels low?  If they were just a little low I wouldn't be concerned but I have had them below 1.0 more than once at 8am ( and that was with urine test too) and the test finding from Endo I don't have but was told I had a "little" but not sufficient level by far.  I have had trouble with fatigue that is almost causing me to be bedridden along with nausea and abdominal pain.  To doc's credit the nausea and stomach pain came on after our initial meeting and I didn't get to tell her but I have since told nurse to report it.  It is important to note that I had nausea, abdominal pain and low blood pressure for 9 months (lost 20 lbs that I didn't need to lose) but  this was just a about 6 months before cortisol was EVER checked.  I have also seen 2 GI docs who have run CT scans, ultrasounds, endoscopy, the works but find nothing.  This "appears" to be Adrenal Insufficiency to me.  Can someone give me some suggestions?  Thank you!

[SarahB79]

There is actually an adrenal insuffiency forum on here... they may be able to help you more.  

I recently saw an endo in cleveland that said it was impossible to have insufficiency if you have normal or low ACTH.  Obviously with your case that is not ture... and I have seen others present with the same thing.  

Have you had other hormones checked like thyroid, LH, prolactin?