FORCE: www.facingourrisk.org/
Genetics: https://www.genome.gov/
BRCA1: https://ghr.nlm.nih.gov/gene/BRCA1
BRCA variants app: https://brcaexchange.org/
There are various groups on Facebook, search for key terms like BRCA, hysterectomy, and mastectomy.
I read a lot of folks issues and posts in multiple facebook groups - this is good, but you need to take that with a grain of salt. Posting is always heavy on the 'negative' side because that is when people need the most support. Don't let it scare you.
Everyone's experience is different. Go with your gut and find surgeons with experience that you trust. They have done this a lot and they know how it is going to go and what recovery is going to be like. Ask a lot of questions. Feel comfortable with your choices.
Find local support groups. Use the FORCE peer connections. Talk to people that have been through it. You can do this.
The only thing I purchased for the mastectomy was a shirt that had pockets for the drains. I was glad I did this, it looks nice and it did help. However, my favorite way to deal with the drains was with a carabiner clip just hanging on my pants! Criss cross them across your body if they are too long.