Don't panic! How soon do you need to have this taken care of? My next question...does it matter what *kind* of underwear you wear on stage? I'm thinking this whole issue might be avoided with boyshorts, but if that's not an option, you're still going to be okay.

Do you have some shaving cream? A nice new razor? If not, and if you can, get those things. Then get some warm water (it can be in a cup, really) and a washcloth and a towel. Then hold a nice warm washcloth over the area you want to shave for a minute or two. Rub some shaving cream on (think of it as relaxing!), and shave the area you need to shave carefully, but firmly. Rinse the razor in the water frequently, and know that you may need to go over the same area more than once. When you're done, wipe off with some of the water and a washcloth and dry yourself with the towel. Apply some gentle, preferably unscented moisturizer (If you have any kind of sensitive skin lotion, that's probably fine.)

Above all, know that nothing truly horrible will happen. It might seem awful and upsetting at the moment, but it'll all be over with soon!