LG, I would probably just stop taking the DHEA although some is needed to make cortisol too. Yes, in your case it is probably the long term fentanyl. In post menopausal females (and this includes surgical menopause), the adrenal glands are the place where your sex hormones are made. The strong opiate has suppressed this gland. As you wean down, it might come back.
I have been treating my adrenal fatigue with herbs since March. I added in the DHEA around September (before that I had the pellets). I stopped the opiates about 3 months ago now (I think...it has been a big blur) and I have had two normal periods the past 2 months...so the body can reset itself. I just know I have been slipping with the diet part and need to get back to it. The body takes about 18-24 months to recuperate from AI. The fact that I have been taking kratom during this time tells me it affects my system differently than oxycodone and morphine did.
For you, I'd just stick with the HRT. It's working.
Mel, I know today was tough but you got through it without relapsing! That is awesome my friend! Your hormones will reset themselves too and for you, if I recall correctly, you are a bit younger. Your hormones should reset better than those of us in or nearing menopause. I know that doesn't make you feel better right now but know it should get better soon. It's funny that you mention the sex drive thing because today was the first time in a long time where I actually thought about sex! I'm pretty happy about that. I thought my drive fucking died and was buried.
Hang in my friend and take this shit one moment at a time.