I completed menopause naturally without surgery at age 46. Granted it was earlier than average, but...it is not unreasonable to go to menopause now.
You can read my surgery story in my profile. I had both ovaries and tubes removed at age 48 in January. It will give you the whole lowdown on what to expect regarding the surgery, but I have no idea what surgical menopause is like. If you were in your 20s or 30s I'd say try to save an ovary. At 45, no way. From what you described, they need to go.
I would honestly get a second opinion. If they could possibly save one ovary? I had a hysterectomy in my thirtys and cannot begin to tell you all the things you will experience. If they remove all of it, you will have no hormones and with cancer in your family probably not a good idea to do hormone therapy. Seriously, opt for a second opinion before going under the knife.
Hi and welcome to the forum. I think you will find the support and advice you want on this forum. It is full of wonderful women who are willing to give great advice and their own experiences. One thing to keep in mind is that if your are pre-menopausal then a CA125 isn't always accurate. When you come out of surgery you can expect to have hot flashes, mood swings if they do not put a hormone patch on. Even if you do get hormones, you may still experience these things until your body gets the estrogen level up to where it need to be. I am glad that you doctor is being so active in your treatment. I think that you will find that you feel so much better once surgery is over. It always amazes me how much better I feel after surgery compared to before. Do you know when your surgery will be? Are they doing a laparotomy or doing it laprascopic? Please keep us informed on how you are doing.