No!!! Do not underestimate step II. It is much more difficult than the released practice questions. I was getting like 97% on the practice questions and I didn't get anywhere near that percentage on Step 2. Don't get me wrong, I still got a great score, but the test was much more difficult than the released questions. I would compare it best to the national shelf exams.
Now I know your test is in the morning. If you actually read this tonight, don't panic. Everyone takes the same test and you're compared against how other people do on the test, not on how you do. Just realize that it will be more difficult than you think.