Hi DD06,
Since you are interested in some highly-competitive Schools, you would likely find it beneficial to speak with an Admissions Expert about your overall profile and plans. Those Experts should be able to answer your Admissions questions and help define the specific areas of your profile that could use some improvement (and the more time that you have to work on those areas, the better). There's a Forum full of those Experts here:
https://gmatclub.com/forum/ask-admissio ... tants-124/Many Test Takers spend 3 months (or more) of consistent study time before they hit their 'peak' scores, so it's likely that you just have not put in enough time and effort yet. In addition, statistically-speaking, raising a 580 to a 730+ will likely require that you commit to at least another 3 months of consistent, guided study - and you'll have to make significant improvements to how you handle BOTH the Quant and Verbal sections. With a mid-March Test Date, you would have no more than about 2.5 months of study time though. Thankfully, the GMAT is a consistent, predictable Exam, so you CAN train to score at a higher level. Since you're not facing any immediate application deadlines, you might want to consider pushing back that planned Test Date (although you don't have to decide either way just yet).
The OG books are great sources for practice questions, but they're not designed to teach you Tactics, patterns or the little 'secrets' behind the GMAT - for those, you'll need Course-oriented materials. To that end, you might want to work on the OG a little later on in your studies. At this point, you can begin your studies however you like, but if you're looking for a Study Plan with materials and CATs/mocks included, then I'll be happy to offer some suggestions.
GMAT assassins aren't born, they're made,
Rich