My advice, first of all is that even it something goes awry, at the end of the day, if your are married to the person you love, then it's been the best day ever! There's a lot of stress in preparing to spend the rest of your life with someone, or rather, preparing for the day that becomes a reality.
Take a big deep breath and enjoy every moment of the preparation, the decision-making and the follies that will accompany trying to create a flawless event involving more than one person. Let your day be fun, and allow yourself the space to laugh all the way up to and down the aisle. It's one day, enjoy getting there.