Please be very careful with online support sites, as it is possible to re-traumatize yourself if they are not run well.  Many groups on Facebook, etc., are set up by people still enmeshed in their own trauma, and this can often set up power struggles and other nasty situations.  Check the reputation with many sources, look for groups set up and/or moderated by professionals, or a wide range of moderators.  Be careful of the information you give on these sites, and if someone seems too friendly too fast, that's a good red flag to heed.  Proceed with caution.
Pandora's Project (Pandy's)
Providing information, support and resources to survivors of rape and sexual abuse and their friends and family, since 1999.  Pandora's Project offers peer support to anyone who has been a victim of rape, sexual assault, or sexual abuse through their online support group, Pandora's Aquarium.  They also maintain a list of Crisis Support and Hotlines, and an excellent collection of resources.