"When you are constantly in that “fight or flight” mode because of stress, your adrenal glands will produce additional cortisol and adrenaline. This is a normal bio-chemical process. The problem is that in order to make cortisol, your adrenal glands need progesterone. This causes your progesterone to be used in making your stress hormones, as opposed to what it is designed to do —support your pregnancy.

The adrenal glands cannot make cortisol without progesterone. Often referred to as the ‘progesterone steal,’ your body will steal however much progesterone it needs to make cortisol. "

http://www.cbn.com/health/nutrition/drlen_051507.aspx



That's one common route for high progesterone to cause high cortisol.
If you're using cream luteal then it's likely your body is using most of it for cortisol - especially as you've had stress for a long time.
Did you take prog. cream due to low levels?

It's hard to control what the body chooses to make from cholesterol to hormones. When it definately is stress related then adrenal hormone output will need to increase so focus on cutting out as much as you realistically can.
Give your system a chance to de-stress.

If it's not stress and an isolated adrenal problem causing real Cushings that'll be identified if you're being tested for it.

Until you get those results focus on de-stressing and really focusing on yourself and self-nourishment.

Some might say to stop the prog. cream but there is the possibility of your body then using other hormones to make cortisol (creating other imbalances) - so in a way you are supplementing cortisol without using hydro-cortisone by using the prog. cream. If you still have high stress and suddenly stop the prog. cream it could be a rough ride.

If you do stop the cream, taper down the doses slowly allowing your endocrine production to adjust slowly to the change. Never stop hormone therapy suddenly.

The ultimate route would be to be ruthless with cutting out stress, while tapering very slowly the cream...bringing your system back down gently.
That's IF stress is the cause. Your test results should help give a clearer picture.