Hi Michelle,
I can tell you from my experience that low estrogen levels along with low testosterone levels basically leaves you feeling like a post-menopausal woman. I was having hot flashes, insomnia, and heart palpitations. My estrogen level was about 40-50 pg/mL. This was while I was on two twice-weekly transdermal estradiol patches. After months of this, I finally consulted another endocrinologist who supplemented me with oral estradiol. My hot flashes and heart palpitations have stopped, and I am sleeping better.
~Terri