Oestrogen dominance seems to be a misunderstood term. It simply means that you aren't producing enough progesterone whilst also having oestrogen surging high. For many women in perimenopause this can be higher than any time in their life.
I think the term comes from when birth control pills were known either as oestrogen dominant (like Brevinor) or progesterone dominant (like Loestrin), because the volume of oestrogen against the strengths of the different progestins can tip them in either direction. ‘Pill ladders' were created for GPs to start in the middle with Microgynon (slightly progesterone dominant) and then go in either direction dependent on oestrogen or progesterone dominant symptoms to redress the balance.
I also suspect that many newly post menopausal women still have surging oestrogen and the simplest way to know if HRT oestrogen can help you is if you take it initially on its own and then you'll know if it makes you feel better or worse. Blood tests aren't reliable as hormones are volatile and can rise or fall at any given moment, especially in perimenopause.
I've used progesterone cream successfully in peri, which does get your levels up and you feel energised, motivated and the anxiety goes. It's possibly a combination of it creating a smaller gap between oestrogen and progesterone (this causes the least symptoms) and progesterone's influence on GABA, the calming neurotransmitter. The micronised progesterone should also work but it may be a harder one to get the dosage right with, as it's oral and not transdermal. Vaginal may work better for you.
Some women also use high doses of oestrogen, or the combined pill, which both work to override the volatile cycle, where the brain down regulates its own oestrogen production due to consistently high levels of oestrogen in the blood.
There are many theories why oestrogen surges in perimenopause, it could be a dwindling egg supply causing more oestrogen to be pumped out or multiple attempts to release an egg in the same cycle. Who knows, but it's incredibly exhausting and, at times, very frightening.