I used Ucertify, Pluralsight, linkedin training/lynda and quizzlet. I also googled free practice tests and used a few free demos. the more sources you use the better. Even though he is a contributor to the exam, I dont like Mike Myers courses. They only cover the absolute basics. I like the Sybex books. Right now the exam kit is $60 on amazon.
Sounds like you may be getting nervous and either forgetting the answers or misreading the questions. One of the things they do to make the test more difficult is odd phrasing. Make sure you read the questions and answers carefully. Any that you are not absolutely certain of mark and go back to at the end.