nothinglessthan780,
I like your revised plan to take a month off and then launch another 3 month assault on the GMAT.
You said you were scoring 600-670 in your practice test. Which tests did you take? If they were good tests and you scored so much lower on the real exam, in my opinion, one or both of the following are happening:
1st possibility: You experience
high test anxiety. This happens sometimes with people who feel a lot of pressure (you mentioned that everyone was looking at you and expecting you to achieve) and have trouble focusing on the test alone. During your test if you find yourself wondering what others will think, how you're doing terribly, how your time will run out, how you're probably making careless errors etc... You may have high test anxiety. This is debilitating because it keeps you from focusing on the question at hand.
I think everyone gets anxious for the GMAT because whether we admit it or not, it's a big deal. If you think test anxiety might be a major problem for you, have a look at a book I've used, called
Taking the Anxiety Out of Taking Tests by Susan Johnson (ISBN 1-57224-068-7). It's old but it's great

. I've also attached a document for combatting anxiety that you may find helpful.
*Get it here:
https://www.ets.org/Media/Tests/PRAXIS/p ... nxiety.pdf
2nd possibility: You spent plenty of time studying, however you
studied "hard" but not "smart" Did you follow a rigid study plan? Did you spend time going over each question? Did you track your progress for specific topics rather than just overall score? Someone else has mentioned, and I would agree 100%, that studying yourself (how you work, how you think, why you pick particular answers) and studying not just what the right answer is, but WHY it's right is extremely important.
This 2nd point was my own downfall. Before my first exam, I studied hard but not smart and I had so-so results. I did much better the second time around. Take a look at my debrief for details
https://tinyurl.com/gmatpost
I hope this helps
* Moderator's note: Added link for ETS reducing text anxiety.