Dear Kathy1004, The purpose of the Tamoxifen is not to keep you in menopause but to block estrogen, particularly in breast tissue. Your doctor may have been referring to the use of Tamoxifen rather than another class of hormone therapy - aromatase inhibitors, when talking about making sure you were in menopause. The aromatase inhibitors may be used in post-menopausal women, but are not indicated in pre-menopausal women. Tamoxifen is the adjuvant hormone therapy used in pre-menopausal women.
A hysterectomy would not take the place of the use of Tamoxifen. Women have different degrees of symptoms of menopause and it is impossible to predict a person's specific reaction.
In regard to your symptoms I am copying for you a link to a section of the website chemocare.com regarding chemotherapy- induced menoapuse, and some common symptoms and suggestions for management (http://www.chemocare.com/managing/fullstory.sps?iNewsid=24403&itype=1875). You can also look up the medication Tamoxifen. Hopefully there may be some additional information that will be of help to you.