We all have to realize that PTSD/trauma hijacks your nervous system and makes changes to your brain that can bring about a myriad of problems. For those of you that are scientifically minded, and not worried about hearing detailed trauma stories, I recommend the book "The Body Keeps the Score." This book is not a self help book but a good detailed explanation of the body symptoms that many experience when they have PTSD.
I too suffer with this sleep issue, which may actually be compounded by sleep apnea. Sort of a sick cycle where you stop breathing, oxygen drops, brain sends alarm signals that you are dying because you are not breathing. This surges adrenaline which makes you wake up and your heart will race. Then, if you are an anxious fella like I am, you tell yourself all sorts of creative things about what is happening to you. This makes the entire situation worse and keeps your body releasing all those fun chemicals that make you feel as though you are in a life threatening situation.
PTSD makes it so that your brain has trouble identifying what is life threatening and what is not. Good therapy with a well-versed therapist, yoga, progressive muscle relaxation, and mindfulness are all great tools. Medication can be helpful for many but the other interventions tend to have longer lasting effects and less side effects. Some need meds though to get through and that's ok. Just know that you will not keep the benefits of the medications after getting off of them. They only help while on them and when you stop, there will be a rebound effect. As long as you know that and are prepared for it, it's manageable.
Sorry if this sounds educational in nature but I hope it's helpful. I also have an issue with this problem...very upsetting and frustrating. I've felt defeated about this problem as recently as yesterday. Keep the hope...I say that for myself and for all of us.