When my daughter was being treated for PTSD I learned a lot from her psychiatrist, who is married to a neurologist. PTSD is caused by physical changes to the brain. When trauma happens the brain is flooded by hormones/steroids and certain areas change not only in function, but size too!
Amy, if I win the lottery I'm sending you to neurofeedback. It retrains the brain and dramatically speeds up the entire process. I wish this stuff was covered by insurance! If you have a psychologist or psychiatrist with your insurance who practices EMDR, if might be a good idea, too.