hi...i don't want to get all philosophical here but there is something i would like to add...
i read once that when ever you are feeling low, try to remember the face of the poorest person you have ever seen and you will start feeling better...
maybe you should not take of GMAT as a make-or-break thing....you will have other ways of achieving your final goals, only that they might be slightly longer....i think that once you manage to completly forget about GMAT, while taking GMAT, you will be able to do much better...again....easier said than done....
and may i also add...you don't need to put in hard work....you have already tried that...you need to put in "smart" work....the link that Paul has posted, is a good read...
and lemme see if i am able to apply all this to myself....i taking the test tomorrow