A true friend will understand Julie! Being uncomfortable in social situations doesn't make you selfish and certainly doesn't mean you don't care. Take your friend to lunch and have a good old chat about the whole thing. Let her know that you care very much about her and her special day and how honoured you were to be asked and how you could help out in a different way. I hope it goes well for you xx
Thank you for saying so. I do feel like crap about it, my friend knows what I'm like in public places like the kids school, around people etc anyway.