What Free to Shine said is good advice.
When I left as a child, I suffered nightmares for many years on and off. I think it's perfectly natural after the traumas you have been through.
Then I didn't have them for years, having blocked them from my mind. Six years ago after an encounter with an e-meter, I started having the night mares again. PSTD is far more prevalent in Ex scientologists than one could possibly imagine and it takes a lot to recover from.I was very ill for about a year and it took all my strength and determinism to conquer this, initially it would have been very easy to give up, but something I learned long ago was I was not prepared to give Scientology the satisfaction.
Stay strong, avoid stress. Do get outside help, even if it is just talking to other people who have suffered similar or the same problems. Better yet, get some professional help, not all psychiatry or main stream counseling is the big ogre Scientology makes you believe.But do be very careful not to get counseling from bogus Scientology practitioners who advertise their "expertise" as bonafides in our society.More scientology under any other name is not going to help your condition.
I also personally recommend long walks in the countryside, observing nature can be very uplifting and a stress reliever. It might not be for everyone, but one of the biggest helps for me was facing my fears head on, initially this was even more stressful but as time has gone on, those fears have subsided. Protesting against Scientology, which was my biggest and deepest, darkest fear has had remarkable results in my healing.
Something I have always had trouble with is reaching out to people for help. This was ingrained in me as a child, not to put "entheta" on other people's lines. This is also a method of control and stops you seeking help when it is most needed.
There are many people who will help you, don't be afraid to ask for help.
I wish you all the best.