The # incorrect (or the # correct) is pretty much irrelevant - that's not how a CAT is scored. On the real test, you'll get about 60% of the questions correct, regardless of scoring level (unless you're below about 450 or above about 720).
The bigger issue is that it sounds like you took this test from a paper, physical book. That means the test was not an adaptive test. That means the practice test cannot be compared in a valid way to the real test. You need to take an adaptive practice test, ideally one that uses the same algorithmic theory as the real test. (Ours does; I don't know about 800score.)
Next, DO NOT take 5 tests in a week. There's really no good reason - ever - to take a practice test more frequently than once a week.
CAT exams are really good for (a) figuring out where you're scoring right now, (b) practicing stamina, and (c) analyzing your strengths and weaknesses. The actual act of just taking the exam is NOT so useful for improving. It's what you do with the test results / between tests that helps you to improve. (And once you've taken one tests, you know what your results are - taking another test the next day isn't going to change that.)
So, take ONE MGMAT* practice test, under full official conditions (2 essays, 8 min break, quant, 8 min break, verbal). Do not use the pause button. Then use this article to analyze the test and figure out what you need to do to get better:
http://www.beatthegmat.com/a/2009/09/23/evaluating-your-practice-tests*Note: I suggest taking an MGMAT test for several reasons. First, I know it's built using the same algorithmic theory used by the official test. Second, an MGMAT test will give you specific reports / analysis on your performance. Third, the article I linked above tells you how to analyze MGMAT tests in particular.
Your score on a practice test taken about 7-10 days before the real test is indicative of your performance on the real test. It's rare to see a major score change in the last week or so. I think we're approaching about the 10-day-before mark right now, so I would advise that you use your score on the MGMAT practice test to make your decision (as to whether you keep your test date or postpone).