I think your default setting is to take blame because it's what you've been trained to do, and that's sad.

I think it is possible to separate feelings toward TT--or the lack thereof--from your potential feelings about yourself and your experiences. Also, processing trauma is multi-leveled: there will be times when you feel no emotion and other times when you feel overwhelmed. I think this is largely driven internally, though sometimes when our "soft spots" intersect with a T's technique, it can seem to direct the process. What stops you from bringing up your lack of feeling to TT?

I think you're a much better judge of people than you believe you are. But what's difficult is separating the internal defenses from the perceptions. You're in control of this process--the timing and depth of your trauma work is for you to decide. You needn't feel as though your T makes those decisions. Perhaps as you can de-emphasize her control, you can begin to feel more comfortable.

Your change in living arrangements is unsettling, and it would have been better if all the parents stepped back, but realize this situation isn't unique to you. I can't count the number of students who've talked to me over the years about room-mate issues--and I remember my own struggles with rooming. Some of this is a bit of a right of passage. I hope you can find other arrangements without too much hassle.