Hi Suzy, the lead up to mastectomy for me was the hardest few days. The unknown, the fear and the emotions. I recalled how I managed in this post, not sure if you have seen it so here is the link. And I was terrified of regret. http://www.bcna.org.au/network/groups/61026/blog/67893
Everyone is different of course, and you will do what is right for you. If you feel like ypu are losing control perhps ask your GP for an anti anxiety med. This helped me alot leading up to and post surgey which was a very emotional time also.
Good luck and I hope you let us know how you get on,
XXX Louie