Since your cortisol levels are so low you will probably need to supplement cortisol in order to feel any significant difference as your adrenal glands are healing. A good source of information is SAFE USES OF CORTISOL by Dr. William Jefferies. You can obtain natural cortisol supplements from a physician who will prescribe Cortef...or you can try Isocort (available over the internet) which contains 2.5mg of natural cortisol per tablet. I have used Isocort with excellent results.
No need to worry about DHEA as long as you are not taking it as a supplement. The herbs and glandulars will not raise your DHEA levels to an unhealthy level.
You might also find some valuable information about adrenal fatigue on Dr. Lam's website...he has an excellent protocol for healing adrenals. I'll post the link for you in a follow-up post.