Taking my test in 2 days, please help

[Rapt0ria]

I have waited ONE year for this test which I'm going to take on May 26, 08. I spent 4 months JUST for Barron's 3500 vocabulary building and then I kept revising it up until now, so I have quite a command over it. I have practiced a lot in Verbal section & I'm sure I'm going to to do well.
Now, I spent 2 months going through all the definitions, practice exercises and everything in Barron's & PowerPrep, both of which are the BEST for Quantitative section. My average correct answers in the beginning were 18 out of 28. Later I jumped to 22 out of 28 but could never surpass that. I bought a few tests from online test prep websites but still I'm not improving. I don't know what to do now as I read that real test questions are much harder than Barron's & PowerPrep.
Can anybody help me before tomorrow, May 25, 1:00pm GMT? I mean, any kind of tips. I have a problem that I usually solve the comparison questions instead to comparing them.