Hi Gilmoree,
I was exactly your age when I had my hysterectomy. For different reasons (prophylactic surgery).
It WAS instant menopause, but other than the first 2 months or so, it was fine. Hot flushes etc. They lasted more or less for 5 years. I do still get the occasional flush now but barely noticeable (8 years on).
The first two months, the flushes made me feel really ill, as if I could pass out. But as I said, after that, completely bearable.
What I would say though, is the hysterectomy surgery is SUCH a doddle. I woke up the morning after (I always have a bad reaction to general anaesthetics and am out of it for 24 hours or so) and genuinely thought they hadn't done the surgery. No pain, no discomfort even.
Do take it easy afterwards though. Although no pain, I over did it and then suffered. I should have just rested for a week or so. I was back at work (as a full-time secondary teacher) within 4 weeks.