Well, you have been hurt, it's understandable that trusting is such a challenge for you. PTSD does have these symptoms of detachment, I experience that challenge myself and I have made some gains on it because I am more consciously aware of it now. I think each individual has to work through whatever areas they were hurt, have it validated and slowly work towards developing a sense of personal boundaries and control again. You have to understand you are human and all humans experience challenges of trust on some level and what helps is seeing how you more apart of then separate from and alone.

Have you worked with a therapist?