I feel like it's even worse than the title because she isn't just a friend she's a friend in my therapy group. Their names are vaguely similar, will go with Cameron and Karen (Changed obv.), not the same but close enough where you could reasonably make the mistake. It's was during a super light hearted topic and we were all laughing and talking and Cameron had helped me figure something out and I just yelled thank you, Karen! And I corrected myself immediately and for a split second I was just gonna laugh it off and move on but it was like someone had just hit me in the chest with a wrecking ball. I started sobbing and all I wanted to do was catch my breath so I could at least let the therapist know what was happening. I was finally explain that I had just called her by my assaulters name, the therapist was reassuring me and letting my know that the group was giving me so much support in the chat. Cameron spoke up and in like a super bright and cheerful tone, and used something her and I had been talking about the day prior to help calm me down to the point where I was able to process what had happened. Cameron went on to explain that she wasn't offended or mad that I had called her Karen, which I had been vaguely worried about. Mostly I just felt like I had invited a monster into our safe space. I'm so thankful to the therapist for handling it so well and too my friend for being the one to help me out of it.

TL;DR Called therapy friend by assaulters name, had a breakdown, friend helped me out of it