Hi, I Was Dx With Breast Cancer, Estrogen Fed Last

Hi, I was dx with breast cancer, estrogen fed last May, had lumpectomy and 3 weeks of radiation for stage 1 with clean margins and no lymph involvement. The only rx I am pushing back on is the femara, I am so fearful of the side effects. Please let me know if you think that is needed. In the beginning of this the MDS stated that with my particular cancer they were not recommended necessarily the need for taking the femara but now are now stating I should take it. I have read some statistics and would like to know if this would be a life saving medication??? Thanks you so much for your response
Joann D RN