Sharry, welcome to MM!
42 is far to young to be oestrogen deficient and I would urge you to start taking HRT as soon as possible. As DG said, bio identical Oestrogel is the best form of HRT (and virtually risk free) to use and because you have had a hysterectomy, you will not need the dreaded progesterone which is the problematic part of HRT.
The gel is fantastic and I would go as far as to say life changing. I use 2 pumps every day and it is the best form of HRT I have used by a very long way.
You may be interested to know that although I do not have an underactive thyroid, blood tests have revealed that my thyroid readings are far better when taking oestrogen - my cholesterol is much lower too.
There is no need to suffer menopause symptoms, you have a choice and don't forget, those symptoms can drag on for years making your life a misery. Oestrogen is like a control centre for so many vital functions and oestrogen deprivation can cause all sorts of health problems in later life.
Hope that helps.