This may bear checking out with medical people but not for those taking Tamoxifen as there are contraindications.
When I went thru menopause with hot flushes , night sweats , insomnia etc I tried a product called Remifemin which I understood had been used in Germany since the 50s for menopause symptoms.It is a refined version of a herb called Black Cohosh used by native Americans for female problems.It is not oestrogenic but a hormone balancer I believe.
I had tried HRT but had difficulty with progesterone.Anyway I found this product gave me my life back reducing the hot flushes , night sweats etc and enabling me to sleep.
This was 20 years ago , I was 40 going thru a savage early menopause holding down a very busy academic career as well as caring for my first baby.
Remifemin is available in supermarkets and chemists but please talk to your medical team before trying.