Losing sucks, sure. But one of the things that a lot of wise fighters and fighters who have been through a lot understand is, even if you lose a fight, in the grand scheme of things it has no real significance. The sun will come up tomorrow and you can handle it. In fact, having this knowledge can actually improve your performance because it can often allow you to put down that weight you've been carrying around worrying about losing. Losing won't dominate your thinking and you can just go out there and be free to compete and perform at your best.