Does your bride know that you are working on staying sober? Also, how many bridesmaids are there? Can you find an ally there to remind you? If there are a lot of bridesmaids and it's a big wedding, I imagine they need a designated driver/buttoner...as one comic calls it, the "We Gotta Go Girl."
People might forget that being a bridesmaid isn't just a matter of standing up in a dress. There are parties and other events involved.
Hang in there and keep posting.