First off Jenn, I feel your pain. What you feel right now is completely understandable and you have the right to wollow in it. This test was a real bugaboo for me as it has been for most. I was scoring in the 700s on all my practice tests (except Kaplan) and I got a stinking 610 on the real thing. I knew I could do better, so I studied some more, took it again, got a 640. Still not satisfied, I studied some more, took it again, got a 610. Yep, I went down. Imagine how I felt. But I told myself that the GMAT is just a test, not an indication of IQ or absolute B-school ability or good looks or charm, it's just a test of a few concepts and time management. I got too nervous and rattled when I had to guess and overall I just wasn't positive in my previous tests. I took a month to remedy that and I took the test again (4th time) and got a 710 (remember, there was only 1 month between tests).
Second, 660 is a great score. I know you did not do well in quant part, but at least you know where your weakness is. One thing to note is that a low GMAT quant can be overset by high quant horsepower in your job. I know you want to apply to school this year and apply in the second round (I can see by your dec 12 deadline that you are applying to Haas). You can't re-take the GMAT until next month, so the earliest you can take it is Dec 1. Will your official scores make it to Haas by dec12? Maybe, but I doubt it. Here are a couple of options
1. Apply with what you have. Really shine in your essays and LOR and prove to adcoms that your high quant job is indicative of your quant abilities.
2. Maybe apply to a different school that has a second round deadline in early January. This way, you can study up on your quant, stay polished on your verbal, re-take the test in early Dec, and have your official scores ready by deadline.
3. Wait until next year. yea I know this is not what you want to hear, but I had to go though making that decision a year ago after I got a 610. IN the meantime, work hard on your GMAT to improve it and have your essays, etc ready for round 1 next year.
Overall, you doing great and your working hard and it will pay off, I promise you. Take a day off and relax, talk it over with friends and family. If you decide to re-take try to work on your time management and your mental attitude. Stay positive. YOU CAN DO THIS.