In sales you don't get as many opportunities to *do better*. Many companies it is sink or swim, has nothing to do with your work ethic necessarily.
Use Gonelifting's advice and look on this as a POSITIVE OPPORTNITY. No need to overthink it. Just look at it this way, "The company/this position and I were just not a fit for one another..... NEXT!"
I know it is easy for me to say, but similar circumstances have befallen me and every single time it was an incredible blessing in disguise.