Ambra, I don't know your T so I don't know why there's hesitation to tell her. You've done nothing wrong. The problem is your mom and you're stuck in her house. I would not hesitate to say why. As other posters said, a short email or text, with a short explanation is in order. If you're thinking of doing something harmful to yourself, as in having a plan, you may have to ask T to call. Otherwise, as sd and others suggested, asking for an earlier appointment.

Like::: T, my mother read my diaries about CSA and ED. I'm scared and feeling SUI. I'm in crisis. Then ask either for her to call or if you can have an appt early in the week. That's short and to the point and gets the message across.

Even if your T has strong boundaries about contact outside of session, no T wants their patients to be stuck in a real crisis, feeling sui. As Brown Owl said, there's a difference between an email just venting or attempting to do therapy outside of session and an email about a real crisis situation.

At the very least, ask for an earlier appointment. There's so much to figure out. Not just how you feel, but can you live at home, can you afford therapy. Practical matters, as well as emotional ones. Hang in there and keep letting us know how you feel as the weekend progresses.