One of the things I most want people who have trauma histories to know is this: you don't have to trust everyone. You don't have to trust me. Meeting people, especially those you are "supposed" to trust, may create in you a frisson of fear. You experience intense caution around others because you have been through something, perhaps many things, that hurt you. Emotional pain. Physical Pain. Abandonment. Childhood experiences that you cannot erase no matter how hard you try. You did not experience these incidents in isolation and so you may be vigilant around other people. That's okay. Fear is a normal reaction when you have experienced trauma. Trauma itself is defined as a "normal reaction to an abnormal experience." You don't have to trust someone when you meet them. Allow yourself to understand the protective nature of your fear and then allow your boundaries to soften. Some person hurt you. Every person won't.
Trust when you are ready. It's not a race.