Hi Leah123, I get some tremendous anxiety, and it's often heightened when my T doesn't get it or say the right thing.
All I know that helps is to break every moment down into individual pieces, individual tasks and refuse to let yourself look beyond the present moment. Be strict with yourself and try to stay on task. You rightly say that no comfort sticks for long (which is why I've gained about 12 lb in the last 8 months!) So its so important to take each moment as an individual chunk of time.
What I'm talking about is mindfulness of course, but sometimes it helps to break down what it entails because it's easy to lose sight of its meaning.
Friday is not far away and I know you have a great T so I have no doubt she can help you, but in the meantime try to concentrate on the next step, not the flight of stairs.
Sorry you are going through this xx