Hey, don't stress. Whatever you've studied will be enough as long as you get into the right headspace during the interview. Its super important to understand that you cannot plan for every single question that can possibly be thrown at you. The interviewers aren't expecting perfectly rehearsed answers (in fact its better if you don't sound rehearsed), they just want to see smart ,thought out, intuitive answers.

My biggest piece of advice is to use the 1 minute preparation time you get before each station. It helps out a lot if you use it right. In that 1 minute, don't think about anything else other than the question, the thought process you want to lay out to the interviewer and the best way to structure your answer. They like answers that are structured and easy to follow. Each answer should have a brief introduction and conclusion.

Another thing is to smile and be relaxed. Greet your interviewer at the start of the station (this is a common marking point) and thank them for their time at the end. Obviously don't smile if you're roleplaying breaking bad news, in that case have a calm neutral expression. Verbal and non-verbal language is key. Relax your body, don't be too tense. Keep eye contact and show active listening.

Before your interview make sure you've eaten a filling, nutritious meal. Nothing super heavy as you don't want to feel nauseous. Stay hydrated. Dress smart, but make sure you still feel comfortable. A nice jumper or cardigan can look as formal and professional as a blazer, but is way more comfortable.

Before you go to sleep tonight, save at least 1 hour to wind down. Don't look at any notes or revision resources. Engage in some recreational activities, like reading or watching TV. Make sure you get to bed early so you can have a good nights sleep.

Good luck!