@Bowie. I remember when I was pregnant all those years ago being terrified of giving birth. I'd walk around looking at people trying to get it into my head that for every person I saw, someone had to do the thing that was freaking me out.
It was a bit the same when it came to the mastectomies. I knew there were a shit load of people out there who had dragged themselves into hospital, lay on the trolley and said 'Do' it.'
For me, the node procedures caused more anxiety than the loss of my breasts. I know why that was, but the uninitiated think you will be more concerned about your appearance.
I think your daughter is right, your brain will accept the changes. I used to do most of my crying in either the shower or the car, and I've done more of it before any procedure than I have after. I've had my share of grief, but I've not missed those tits. They were the cause of many problems over the years (they were spectacular) and in the end they were going to kill me.
Good luck. Marg.