Dearest has prepared a wonderfully informative website for us here in Power Surge. One of the most helpful pages on the massive site is the Recommendations Page where it describes all kinds of solutions for various symptoms. You can find it from any page here by clicking on the Power Surge Quick links at the top right of any page or by clicking here for the Power Surge Recommendations.
Also, as you read more here on the boards, you'll see what has helped others - and what hasn't.
You say you're on soy...I've been on Revival Soy for the 4 years since I went off HRT and it's been a godsend for me. There's more information about that on the Recommendations, page, too.
I've never tried Black Cohosh, so I can't offer any experiences with that, but I know that others have used it. There's some discussion on the Alternative Med / Vitamins / Herbs Board.
Best of luck to you and keep us posted