Refused mammogram because I had one six months ago

This sounds like it has been very traumatising to you.
Have you had any counselling to help you process what you have been through.
Your Mum having had cancer too would elevate your concerns and anxiety, over control and testing.
Is she OK? 
I hope that you don't rush into the double Mastectomy. That is a big move. Would you follow with double reconstruction?
Or go flat?
True you wouldn't need to worry about Breast Cancer quite the same, there may still be follow up.
Take your time, thinking of you.