Hi AnnieB
I avoid all oestrogen and phytoestrogens as I've had oestrogen positive breast cancer. There is some conflicting evidence regarding phytoestrogens being contra-indicated for women who have had oestrogen positive breast cancer but I just err on the side of caution.
I agree with you about night sweats - they're horrible. The only things I've found to help to some extent are having a 'Chillow' next to me in bed to roll onto to cool down and having a separate, wafer thin, single duvet (we sleep in a super-king-sized bed and my husband has a thicker single duvet which suits him) . (Chillows are available from Amazon, Ebay etc.).
All the best.