Thank you for all your feedback.

Yes, I think this time I am going to try the GMAT Challenge no matter how much they scare me.
As I have mentioned before, I think the biggest problem with my Quant was that I hadn't looked at those types of questions in a while. I had gone through test prep books first to study, and I only really studied the ones I had gotten wrong... so the types of questions I got on the test day happened to be those that I do know how to solve, but I just took too long to solve them.
BTW... it was surprising how similar the questions on the GMAT and the Official Guide were... basically it was the same types of questions but with different numbers plugged in.
I am going to take a break for a month while I get ready to move... I think it'd be too stressful to plan a move (half way across the country) and be studying at the same time. I hope to give myself 1 to 1.5 months to study after the move before retaking the test. I don't want to take much longer than 1.5 months since it will already be August by the time I start studying and I would like to finish my application process earlier than later.
I will take everyone's advice and buy the
MGMAT math books, then review ALL Quant questions in the Official Guide extensively, then take the GMAT challenge. I will also review my verbal and do some questions from 1000sc, cr, and rc.
Thanks everyone and, again, if you have any more recommendations, I would love to hear them from you. And if anyone has any questions about the test setting, ear plugs, work stations, anything at all that I can give away after signing my life over to take the GMAT, I would be more than happy to help!