Like Roseanne said, there are other things your Onc can prescribe. I took Arimidex for awhile, but lost so much hair, I switched to Tamoxifen. I still have thin hair but not so much. Also a little joint pain. My ER# was 100, so yes, we really do need to take something! I've not been on one or the other for two years.
Hope you are better soon!