I just recently asked my T. if she was mad. She called our relationship contentious and it bothered me until my next session. She has pointed out several times that I project onto her how I used to see my mother react - negatively. I'm always assuming she's mad or frustrated when she's not at all.
Perhaps we should believe that if they really are mad or frustrated, they will let us know. Or, you could ask her to let you know. That way you know she's not all the other times.
She's not going to be angry at you for mistakes you made. You were a CHILD. She is angry at your caregivers who were ADULTS and should have known better. Why don't you take small risks and tell her little things to see how she reacts. I bet you will be pleasantly surprised. When you see her react empathetically, you will rewire your brain that you weren't horrible and it will be a healing experience.