My T has said that trust is something that comes with time and consistency. When someone does something consistently, then we know that that person will do that, or not do that, as the case may be. That is a form of trust.
I used to be afraid every time I went to therapy that my T was going to haul off and smack me every time I walked in the door. Over time, I discovered that she would never raise a hand to me. Now I can walk into her office with more confidence and I trust that she won't do that to me. I do now believe she won't hit me because she's shown me that she won't through time.
Because of that trust, I am now learning what safe means.
(I don't know if I got it exactly right for the word, but that's what I got out of it.)
Good luck as you figure things out. It's a hard concept when a person's trust has been violated over and over. I hope you are able to find the answers with your T.