Wow - Erica I was in your exact shoes this summer. From the time my (now) husband proposed until the wedding was over with, we were constantly barraged with opinions from "well wishing" family members & friends. We couldn't get over how political the whole thing was. "we have to invite so & so because we invited the other so & sos and we don't want hurt feelings". Nevermind that I didn't even know who so & so #1 or #2 was. Or "I hope you don't mind that I invited my friend's cousin's grandmother". Gads.
I knew my friends/ family were going to do a shower for me whether I wanted it or not (just like you, I hate being the center of attention). There were the daily calls "have you registered anywhere yet?".... "you really need to register at a few places".... "people are calling - I need to tell them what you want/ need".
I was in the same boat as you - I had been living with my husband for 5 years, and we really didn't need anything, so finding things to register for was hard.
I told them flat out that if they were even dreaming of having any of those stupid shower games, that I would not be coming to the party. Period.
I felt like my personal life was being invaded constantly, so I ended up wording my invitations so that nobody was invited to the ceremony (other than the people I chose), but that they were welcome to come to the reception. I just couldn't handle being on display for a huge crowd of people, most of which I didn't really know.
I totally understand your frustration.
Don't let them control your plans, don't let them make you crazy.... and it will all turn out just fine.
P.S. Both of my grandmas jumped for joy too!! Lol... we had them be our witnesses at the wedding. It's kinda cool to have our marriage certificate signed by my grandmas.