This is one of the most read pages on the site, so I guess there must be a need for more information of this sort. The Sidran Institute gave me the original list, which I have now removed because it was outdated. Sidran keeps a comprehensive list of U.S. treatment centers but this list is static and may not be updated regularly. Sidran has an excellent help desk. If you need help locating a treatment facility, contact them. If you have concerns about contacting a place over the net, they have a page explaining how the help desk works. If you want to help out, their help desk is currently without funding and run all by volunteers, so make a donation or volunteer once you are better. They will use it to make sure someone is there when you need them and to update their resources to make it easier for volunteers to find the information you need. They are doing great work.
Sidran is US-based. If you are not in the US, you might find help at the International Society for Traumatic Stress Studies database. Along with Sidran, ISTSS has a lot of helpful materials available and is worth a look. GoodTherapy.org also has an international database.
Before contacting any of the centers (unless you are in immediate crisis!) it would be a good idea to look at the post on how to choose a therapist for PTSD.