GMAT Strategy

This is my first post hello to all. I am 36 years old and have not taken a math class on the material tested in over 20 years. Needless to say I am unable to answer any problems from the OG 13th edition pages 20-26 as suggested in my daily emails from beat the gmat 60 study plan. Geometry, Algebra, fractions, decimals all gone, lost somewhere in the back of my mind. Please advise what books, websites (Magoosh or Gmatprepnow)should I use that will teach me in literally baby steps the concepts I need to know.The OG Quant book is more for practice which I cannot do since I don't know the material. I have the KAPLAN premier 2013 edition, but it seems they are more concerned with teaching you tricks to beat the exam and not focused to much on learning the material. My exam is on March 1st, I am aiming for a 570 or better on the exam 55% verbal, 45% Quant. Please advise should I get the Manhattan quant books, or there is another website like Mathhelp.com that teaches GMAT math a 1 month subscription is $50.00. I almost want to take the GRE to avoid all this math, but I have invested over 45 days so far just on verbal alone. BTW i am doing self study and I work full -time so a class is not an option. Please keep in mind I don't have a general idea of the material and would be like an 8th grader starting from scratch.