You definitely will get better with practice. My first time trying PAT was on the ADA's practice test and I got like a 17, which is horrible considering how easy that is compared to the real thing.
But now I'm getting very nice scores on CDP, so I promise you the more you practice you'll get better. I also highly recommend after the test that you go through each and every problem and use CDP's explanations to fully understand how they got each answer.