You need to let your therapist know what you are experiencing. When you get ready to talk about your experiences if it feels that overwhelming, maybe there is something that the therapist can do. I myself am a survivor of childhood incest and adult rape AND I am a sexual assault therapist. I am quite aware of what my clients are going through when they are sharing their stories for the first time. Been there. Done that. Got the T-shirt (literally). Sometimes doing a "grounding exercise" to get you back in the moment helps. Sometimes writing it out and "reading" it helps because it seems less like YOU are saying it. But in the end I have to say that sharing your story is beneficial. There comes a point where it doesn't cause anxiety attacks anymore, or feel like your tongue is going to swell up so big that you wont be able to ever speak again. It takes time. It took me a long time before I told anyone my whole story, but now I do presentations in front of groups of 200 people and can share my story without freaking out *beyond the stage fright thing that is*. It does get easier I promise.