Dear judyv: The temperature variations you are experiencing could be described by menopause. Tamoxifen, which is an estrogen blocker may also contribute to your symptoms. You should discuss this with your doctor. Some types of antidepressants, called SSRI (selective serotonin reuptake inhibitor), which can be very effective in treating depression, may sometimes may help with hot flashes and with sleep disturbances. These drugs can take several weeks before they are effective and should not be stopped abruptly. One such drug which is may be used effectively with tamoxifen is venlafaxine (Effexor). You might ask your doctor if this would be appropriate for you to try.
I am already on .75 Effexor, but this has not helped w/ hotflash symptoms or these cold onsets.