Hi thenerdycat
Experiences can affect our psychology in funny ways.
In this case, you've somehow latched on the experience you had at the test center as indicating something about you.
I'm not sure how well it would work to tell your target schools that your application will be delayed, but I think you should start preparing again no matter how you feel psychologically.
Starting to prepare again will likely make you feel better. It will get you back into reality, which the idea about being a "loser," whatever that even is, is not part of.
That idea is way off, and you know what's funny. Let's even say that the computer going nuts was a sign that you are a loser. Who cares? LOL. You can still go back and take the GMAT, achieve your score goal, go to school, and generally have great life.
In other words, whatever is going through your mind is just disconnected from anything that matters or exists in reality.
So, go do some streaks practice to get back into the game, and let us know when you go back and rock the GMAT.