Kaplan CAT practice test and studying advice...

Hey Everyone, I've been studying for about 2 months now begining in the middle of April, the first month was light but I've stepped it up since. I'm now a month away from test day. I complete my final classroom Kaplan course this Saturday 7/16. I can tell I'm doing better. I can solve almost any question thrown at me. HOWEVER....

1. I feel like I'm taking _way_ too long and have to guess on so many of the Quant questions in the Kaplan practice exams because of time.
2. On the Kaplan test scores I scored 510 on my diagnostic, 560 on a practice test (non-CAT) and this morning scored 520 on my first Kaplan CAT practice test.

I'm starting to get discouraged but I'm trying to keep my head up after seeing a trend of lower Kaplan practice test scores compared with the same person's actual GMAT scores. Over the next four weeks I'm taking each Thursday off work to study for the whole day. I'm going to start reading the GMAT bible (OG) religiously. I don't know if I can do that all in the next four weeks however. I'm done with all the Kaplan online 'workshops' as well as the classroom sessions so now I can devote that time to study the OG, the Kaplan practice tests, and the Kaplan sample problem banks.

I guess what I'm asking is - 1. Will a month be enough time to increase my speed? 2. Should I attack the OG primarily and focus on Kaplan's stuff secondary? 3. Am I hopeless with those terrible scores on the Kaplan practice tests?

Thanks everyone.