Dont worry about it, just take it slow and learn from the questions and answer instead of getting scared. Its probably your first test so yea you got the nerves going and stuff. But dont worry, after you take some more practice test, you will feel at home!
Its too close to be thinking that you dont know your stuff, just think that you've done everything that you can do and go into it without any nervousness (I know thats what messed me up in QR and RC)! I was too busy thinking about how I did in sciences rather than worrying about QR and RC.
Note to myself, worry about whats ahead not whats past!!🙂
Dont worry, you'll do fine!