Idk but from my experience, if you panic, you end up not doing as well as you could've done had you not panicked. I always remind myself that it's not the end of the world if I don't do well in an exam. Technically speaking, you only really need a pass in your exams which isn't that hard to get. I've also noticed, at least for GCSEs, that people tend to get a grade or 2 higher in the actual exams than the mocks. When you're going into the actual exams, act like it's another mock and you'll be fine.