You're off the hook...for now
You say you won't be able to make it to the wedding because your mom is having an emergency surgery. You will have to take care of her 24/7 in the coming weeks and will not be able to attend the wedding. As you apologize profusely, your friend tells you not to worry and is very understanding. She says to call her if you or your mom need anything. You suppress your guilt by going back to fantasizing about your future.