The other salesperson also sent a telegram. Many people beat themselves up when things go awry. Mistakes are the fuel of creativity. Everyone makes mistakes. Try positive affirmations in place of negative self talk.
Successful entrepreneurs keep their positive attitude by being careful about who they hang out with.
Surround yourself with supporters. Good supporters will help you work on contingency plans and help you work around challenges without pounding you with discouragement. They bemoan the economy, the competition, the government, the company, the weather, blah, blah, blah. Successful entrepreneurs also develop their positive attitudes because they feed on progress. At the end of each day, instead of recounting all the difficulties and all that remains undone, write your accomplishments.