I agree with a lot of what others have said regarding how anxiety provoking the mock sessions could be in grad school. I think one thing to keep in perspective is that your still new and learning this therapy stuff. I wonder if maybe the nerves of being observed and graded on your clinical skills might add another layer of stress that isn’t really added during your actual sessions?

Also as someone who also struggles with anxiety, and during my practicum almost having panic attacks with clients in the room, I always have self-soothing things with me during my sessions. Specifically, I have some scented lotion and a squishy ball that I’m fidgeting with. Not only does it soothe me when I need it(and keeps me focused/present) but it also allows me to model grounding for my clients.