Ah yes, its a little known fact that moths love silk as well as wool. Put your dress in a zip lock bag and into the freezer for several days. Take it out and bring it back to room temperature and then repeat the process. It's the changing of the temperature that kills the larvae. Do this with any vulnerable woolens or silks in the same closet.
Unfortunately, when you have the dress cleaned you may find more holes, as the critters leave behind a "glue" that holds the fabric together after they are done chomping. During the cleaning process, the "glue" disappears and you have more holes.
I am so sorry this has happened to you, and wish I could be the bearer of better news.
As far as keeping the moths away, when buying used woolens or silks, always use the freezing process before storing the garment. Hang sachets in your closet, especially cedar or lavender. Don't use naptha moth balls. The smell is vile and you can never get rid of it.
Jody