If she's really a friend she would understand and it wouldn't break her heart. It's her wedding day. Do you think your attendance is the most important thing she's thinking about? Do you honestly believe, on her wedding day, you not attending wold break her heart?
SERIOUS red flag here:
Anyways, I don't feel ready to talk to these people about this thing yet. Right now my sobriety feels very fragile and I KNOW they would undermine.....