Remember that although the wedding is the first (and sometimes only) thing on your mind, your friends, no matter how supportive they are, may tire of hearing wedding talk day in and day out. Ask about other things going on, and remember to discuss other aspects of your lives!
Lastly, give meditation and/or yoga a try. These techniques will not only help you control stress, but it will help you develop the ability to live in the moment. After all, that's what your wedding day should be about.