Bret,
My QB fuselage came from the factory with a crack at that location on both sides. The cracks were only about 1/16" long, so my solution was to just enlarge the existing relief hole with a small grinding bit in a Dremel tool to completely eliminate the crack.
So, I'd say, if it's already riveted up and the crack is very short like mine was, you may want to consider my solution.
Or if it's already riveted up and the crack is longer than you'd want to grind out, consider stop-drilling as Bruce suggested.
Or if it's not riveted up yet, then buying a new skin as others have suggested also shouldn't be too painful. But if it is already riveted up, then I'd make that only the last resort, if you really can't get a satisfactory result with one of the first two options.
And yeah, step back, relax, and have a beer. No biggie. Whatever approach you decide to take, you'll fix it and move on. Par for the course.