I'm glad you are taking the step to reach out, I know how scary it can be, but think it's great you are willing to try it!
You are very articulate and expressive which is so helpful, sometimes I find writing it all out can help me see things more clearly. I was just wondering if it's the same for you.
I'm so sorry your Mom is cutting you off/out like this, that must be very hurtful and painful. I can certainly understand your pain and anger over this. I hope she comes around. However the fact that you are expressing yourself in therapy is wonderful! You must really trust your T.
It's not your fault, I may not know what your issues are but I can tell you with certainty that it's not your fault. This is actually a cognitive distortion called Personalization where you see yourself as the cause of any negative event for which you really were not totally responsible for. And you keep telling yourself those untrue things about faking, and overreacting...feelings just are, they are not wrong.