Our first responses can be the truest ones. So many women feel the way you do for good reason.
It can be a bit tricky, depending on where you live, to get a double mastectomy organised. More a regional than metro thing, but I got some good advice about this years ago. Get your GP to sort out some visits with a counselor and talk to them about what you want to do. That way, if there is any mucking around, a phone call with your permission can demonstrate that you have thought it through and are making informed decisions. It should not come to that but an independent ear isn't a bad thing anyway. Seems like you have already been doing your homework. Good luck.