Hugs, I am sorry you are going thru this!
Like the other ladies said, while it sucks big time, remember the day is for you and your fiance and will be special no matter who is there. I have had some 'drama' with my guest list too and it stings big time. I have shed many tears as well, but trying to remember this is supposed to be the happiest time of our lives. You will have a beautiful day. Good luck!