Hi Christina,
Definitely don’t feel discouraged. The issue is that these tests have different emphasis and content, so on some of them you might do worse than the other ones. If you find an area that you did particularly worse, I would suggest just going over that topic again. I have compiled all of these topics and concepts into a document and study them daily. This has definitely helped me so far. The most important thing for me is to go to the testing center with confidence, because feeling despair and hesitancy, would certainly not help me pass the exam. Keep up with your studies, and all will be well.
I would also like to note, that for the majority of the outcome measures, the MDC value is around 10-20% of the total score. That should give you a general idea when you’re asked a question regarding those.