Just scored a 400 on my Kaplan diagnostic...

I'm new to GMAT Club and I came across the site tonight after looking for GMAT help. After spending the past several hours reading many of the great advice articles, I decided to post my current situation to see if other members might have and feedback or opinions on the feasibility of my goals.

I don't think I'm the stereotypical MBA applicant because I'm 39 years old. My undergrad was a BS in Marketing (with a below average GPA). My goal is to get into a part-time MBA in Chicago, i.e. DePaul or Loyola. These programs have GMAT median scores of around 560.

I'm currently taking Kaplan's "GMAT Advantage-Anywhere" online class. This week I completed the first class and the first online practice test/diagnostic test, with a ego-crushing score of 400 (Q20/V23). I only had enough time to attempt (without guessing) the first 20 math questions and the first 24 verbal questions. I felt like a deer in the headlights during the diagnostic test but it was especially disappointing since I was very familiar with the exam.

In 2003, I took the GMAT twice and scored the very disappointing scores of 440 (Q24/V23) and 420 (Q32/V19). For preparation in 2003, I really did not have a good study plan, despite the fact that I took Princeton Review’s classroom prep course. I feel behind in the class and studied very sporadically over a 9 week period for about 60 hours total (not including classroom time). In 2003, I also took 5 practice tests and had about an average score 490 (Q34/V24). I remember thinking I could have done much better on the exam if I had been more disciplined and dedicated.

Now, nine years later, I’m more motivated and I have time for studying. However, I think my test taking skills may have eroded even more (I’m now 15 years removed from college). I'm wondering if I should put in 150+ hours to see if I can raise my test scores 150+ points. If not, my backup plan would be to attend an MBA program that doesn't require a GMAT or attend an Executive MBA program (assuming I could get accepted, not to mention some eMBA programs also require a GMAT.)

Any feedback or advice would be appreciated. Thanks!

P.S. My gameplan for the now is 1) finish Kaplan's Math Refresher On Demand (it's a review of Arithmetic, Geometry, and Algebra), 2) carefully review my first practice test, 3) complete all of the class homework and workshops, plus review everything covered in first two weeks, 4) take CAT #2.