I recently have started posting as well but have had high cortisol for three years off an on. I have gotten my down before but then stress would send it back up again.
What has worked:
Take a B complex several times a day. I started taking 7 Keto Dhea and noticed it doesn't really lower cortisol but helps my liver.
Part of what I did before is to take 4 - 5 times a day and relax. Reminding my mind and my body I am calm now. This was a huge factor in lowering my cortisol. You can meditate, use Emotional Freedom Technique (EFT), do breathing exercises, or brainwave entrainment using binaural beats. I have a binaural beat meditation on a MP3 player and sometimes have it on all night at a low level while I sleep. Then listen to during the day for 30 min. I also us a healing technique similar to EFT daily to release stress and heal. It takes about 6 week of doing this but it was the only thing that cured my insomnia.
Sleeping 10 - 12 hours a day. If you can't sleep that long lie there and meditate.
Stop drinking alcoholic, it raises cortisol (this is a biggy). No caffeine and stay away from simple carbs.
Excercise as long as it's under one hour helps lower cortisol not too intense.
The rest is an experiment. I also bought Relora 3 days ago. It gave me tension in my head so I had to lower my dose to 1/2 a capsule I am not sure if it's working yet. I tried Holy Basil 2.5 years ago a noticed nothing. Phosphatidylserine relaxed me for two days then after that gave me insomnia. I have been trying Rhodiola but I think it may be energizing my adrenals. I also have 5HTP and mucuna Dopa. I take a very small dose to help relax me. Defiantly trying supplements one at a time for a couple of days help you gauge each one. Good luck and let me know if you find anything that works.