What should I tell my professor

So I'm in grad school and for one of my classes we have to talk about our families in an online discussion. Problem is that my parents traumatized me and I hate talking about family now because it triggers my trauma symptoms.
What do I do? I need this for my grade. Do I ask the professor if I can skip the discussion and why? I've known her for years and know she worked as a therapist at one point, but she is not an easy professor and is not one to let discussions slide and I'm not signed up for accommodations though the disabilities office.