Kat my son is going through the same sort of thing as you.  Have you tried taking your tablets more times a day?  My son is now on 6 doses a day and on a dose of 112.5 mgs of h/c a day, this is because not all the meds taken are actually getting into the blood system.  He like you tires so easily and has some days where he feels better than others.   He has also become very thin and we are concerned about his bone density. It sounds as if you are not getting enough cortisol.  I also understand how you feel about doctors and it isn’t fair that you have to suffer like this.  I do hope that you will find a doctor to take an interest in you and to listen and actually hear what you are saying.  Thank you for your post - sometimes I feel my son is the only one who doesn’t do well.  Good luck I hope things improve for you soon.