I had both ovaries, womb and cervix removed when I was 32 (coming up 5 years ago). The hot flushes kicked in quite quickly, I did tend to suffer mood swings that could be quite extreme (think of my poor husband!). I sometimes had a bit of joint aching. As Cat mentions there was an impact down below too (but then surgery can affect that area too if the cervix is removed)
I sought advise from my local menopause clinic after my oncologist said that as my cancer was not oestrogen receptive I could go on HRT. Initially I went on patches but became intolerant to the patch themselves. So then we discussed implants (I was not keen) or tablets (which I started with reticence). Again I was not completely happy on the tablets so went back for some more advice. I am now using a topically applied gel - which is amazing. Apply once a day to the thigh area and it drys in in just a couple of minutes and off I go! Re. the discomfort in the vaginal area I just use an over the counter lube so that isn't so bad (although you can get medical help if it really does become a problem).
I have also looked at my diet to try to supplement using plant oestrogens - soya products, chickpeas and others all aid natural phyto-oestrogen levels than can help combat the symptoms. I also found being more active (think about weight bearing exercises for bone density and things like yoga/pilates/tai chi) very beneficial on every level.
It was hard at times but I felt it was a necessary evil which I knew I could get through given the treatment I had already had for the cancer.
Re. the surgery - just be kind to yourself - don't push too hard, too soon to do things - listen to your body and you should be fine.
Ok I think that is enough from me! Whatever happens all the best to you and I hope you get the support and advice you need to make the best decision.