It is so hard to relearn to trust, after having it lost so many times. I'm sorry you have had so many hurts. You don't have to trust your t, especially right off the bat. It helps to develop trust in the relationship, and you can do you part by being honest. Telling your t that you don't trust him/her will really help them out. You deserve the chance to know that some people are trust worthy. You also deserve to do this slowly, and using a t for this can be very helpful. I still have moments where I decide I know how my t is going to respond, based on how everyone else has my entire life. It has been a long process to realize that she is'nt my mom, or my abuser, or my old friends, teachers, even old therapists. It can help to make notes of the similarities and differences between your t and others in your life who have let you down. It will slowly give you proof that your t is trustworthy.
All the best!
IJ