Hi there,
I too have had the adrenal stress index (ASI) saliva test and like you my morning cortisol was depressed, corresponding with my complete inability to get going until lunchtime. I have the added problem of my cortisol levels rising in the evening which gives me a lot of trouble getting to bed and going to sleep. You can check out my results in the EiR blog if you're interested -
My Adrenal Stress Index (ASI) Test Results.
Glad to hear you have had some good results with the hydrocortisone. The lack of energy and drive that comes with adrenal fatigue is horrible. I think you're sensible to look for more natural alternatives to hydrocortisone despite the benefits. There is a feedback mechanism that means any cortisol/hydrocortisone you add to the body may over the long run result in the body producing less cortisol itself - and then you're in a worse position than you were to begin with. Having said that the studies I have seen that have found evidence of this negative feedback have used much higher dosages i.e. 20-40mg/day. Still, the risk is there.
From my personal experience I would recommend you give ginseng a go first if you haven't already. For me it acts quickly and doesn't have any side-effects, other than being overstimulating if I take too much. Panax ginseng is most potent so if this is too powerful it's worth trying Siberian which is a bit gentler.
I have also tried licorice in the form of capsules and found it to be very effective. It reportedly blocks the enzyme (11beta-hydroxysteroid dehydrogenase) which converts cortisol to the less active cortisone, thus increasing cortisol levels in the body. My experience is that it does indeed do this. It had me waking up at 7am and feeling able to get up and get on with the day - something I hadn't been able to do for years. However, it quickly began to overstimulate me so I stopped taking it after only 10 days. The worrying part is that the effects did not fully wear off after I stopped taking licorice. I continued to feel overstimulated with a pounding heart and inability to relax. This has in fact persisted for years. I should note that my nervous system and stress response were highly sensitive before I took the licorice so others may get the benefits without the side-effects but I just wanted to warn you. If you look at information on major reputable health websites you will find warnings about it causing high blood pressure and heart problems in some people, so it is definitely something that should be used with caution. Effective but risk would be my conclusion on licorice - so perhaps not such a safe alternative to hydrocortisone!
Besides ginseng and licorice you could look into other herbs referred to as adaptogens - all are used for their ability to help the body cope with stress and promote vitality.
All the best.