I've calmed down a little and am now going to research how long germs can exist on surfaces. I bet they can't for very long. I mean, they can in warm, hot, wet, moist type places...but on your normal surface, only the really crazy (i.e. e. coli) ones stick around, I bet.
All right, WebMD says that most cold-causing germs have a very short life...certainly overnight is long enough for the ones here to die. I feel a lot better now.