First off, you need to ventilate the area as well as you can. Fans in windows, open doors, etc. I get the impression that your drywall got aufully wet. I'm sure that others here will differ, but I've found that drywall that gets that wet will eventually mold, even in dry climates. Check your home-owners Insurance to see if they cover something like this. You may wish to have your drywall replaced. If it's just a small area, I've been able to cut away the infected area and patch in enough to get rid of the mold, taping in with joint tape and compound, and repainting.