Can you try going for a walk, taking a long hot bath, or just finding some way to remove yourself from the stressors for a little while and just breathe?

If this doesn't help. Call your T. You will likely get her voice mail or answering service. The worst that can happen is that your T will inform you of her between sessions policies. Even if this happens it will likely be done in the nicest possible way and without scolding. Ts are good at clueing us in on the rules without beating us up.