Everyone struggles with this - you're not alone!
Part of the task is to understand what your goal is. If you think you're trying to get everything right, then you will never be able to strike a good balance between accuracy and timing. The test does not expect you to achieve 100% accuracy - in fact, it only expects about 60% accuracy for most scoring levels (and even the very highest scores still only achieve 80% or so accuracy).
To start, it's a good idea to read the scoring section of our free e-book The GMAT Uncovered. You can find it in the Extras section of your Student Center. (Note to others reading this: anyone can get this e-book for free by signing up for a free CAT - the e-book comes with it.)
That will give you a better idea of what you are and are not expected to do in terms of both accuracy and timing.
This can also help: think of this as a tennis match, not a test. You're going to win some points and the other guy is going to win some points; you're not going to win them all, right? Your goal is to put yourself into position to win the LAST point. Translated, that means you have to put yourself in position to answer the last question - you have to have time to address it. Otherwise, you've lost the last point, and by extension the match. When the other guy hits a winner, don't go running after it so fast that you hit the fence and injure yourself, thereby hurting your chances on the later points. (Translation: don't go way over when the problem is too hard.)
The test WILL give you stuff that's too hard for you. It does this to EVERYone - you can't get around it.
Next, this article can help with developing better time management:
http://www.beatthegmat.com/mba/2009/12/ ... managementI think you would also benefit from a timing exercise: learning about how long one minute is without looking at a watch or stopwatch. If you don't have one already, buy yourself a stopwatch with lap timing capability. When you go to do a set of problems, start the stopwatch but turn it over so you can't see the time. Every time you think you're one minute into a new problem, push the lap button. When you're done with that problem, push the lap button again, then repeat the process for the next problem. When you're done with the set, see how good you were - and whether you tend to over or underestimate. Get yourself to the point where you're within 15 seconds either way on a regular basis (that is, you can generally predict between 45 sec and 1min 15 sec). Also check your timing for the entire question, of course.
Now, how do you use that when doing quant problems? If you're not on track by one minute, make an educated guess** and move on. (The general idea is that if you're not on track by the halfway mark, you're unlikely to figure out what's holding you back AND have time to do the whole problem in the 1 min you have left.)
** This also requires you to know HOW to make an educated guess depending upon the type of problem and the content being tested. So that's something else to add to your study: how to make educated guesses on different kinds of problems.
Here are a couple of article that can help with educated guessing (one for quant, one for verbal):
http://www.beatthegmat.com/mba/2010/07/ ... s-on-quanthttp://www.beatthegmat.com/mba/2010/08/ ... -on-verbalAll of the above will take some time to perfect - so get to work and come back here if you have any questions or concerns! :)