Try to make sure you understand why you got a low score. If it is because you were nervous, doing bad time management, and made many mistakes that you are sure you shouldn't, then it's ok. Just tell yourself to be calm and careful in the real test, and you will do fine. However, if you don't know why you've got a low score, if you don't understand why you were wrong for the questions that you did wrong, then yes perhaps you need a little more time to prepare.
I don't think you should do another simulated test today. You need to let your brain rest today. Just look at the questions you did wrong and make sure you know why.
Keep on asking, and it will be given you;
keep on seeking, and you will find;
keep on knocking, and it will be opened to you.