Let's say you write five short stories. Two will be terrible, probably. Two will be good. And if you're lucky, one might be really good.
If you think about it, this is extremely encouraging math. By definition, one of those five short stories will be the best. What does this mean? It means if you write five more stories, you'll have yet another best story.
It also means you're playing an extraordinarily simple numbers game. The more stories you write, the more chances you have to write another best story. Can you imagine how good your best story might be if you wrote fifty works? A hundred?
This idea is so simple that it's almost laughable, and it should teach you to be grateful for the things you write that are bad. Learn from them, get past them and move on to the next idea.
One final thought. There's a possibility--admittedly a slim one, but a possibility nonetheless--that one of those hundred short stories has a chance of being truly brilliant. Keep going. Keep trying.