Most of us aren't aware of the chatter that goes on in our mind.  You know you are thinking most of the time but are you thinking about what you are thinking?  (P.S. The concept of thinking about thinking is called metacognition).  If you could be present to these thoughts you might find that a lot of what circles around in your mind is self-criticism.  "Why did I do that?" , "I sounded so stupid!", "I am always saying the wrong thing", "I always lose", "I suck at tennis".  And I am being kind.

When you examine the thought processes that go on in your mind you might see that a lot of your sadness, anxiety, frustration or shame comes from negatively thinking about what just happened.  This is a learned process and can be unlearned.  Most children are criticized by parents, friends or teachers, and even thought it might be very few and far between, these negative messages are imprinted on our psyche and shape how we think about ourselves.

So as adults, it is our job to stop the critical self-talk.  The first step is to catch yourself doing it (awareness).  Next you can find ways to combat these negative thoughts or reframe them in a positive way.  Basically, give yourself a break.  Be gentle with yourself.  Allow yourself to be.  Don's use words like "always", "never", and most definitely adjectives like stupid.  These are self-defeating words that just keep you down.  Mistakes are merely lessons learned and building blocks to a better self.

"Everyone makes mistakes", "I'll do better next time", "I know I did the best I could", "Next time I'll say this...", "Tennis is not my game but I am an incredible golf player."  Changing language changes thinking which changes the way you feel about yourself. 

And remember MY golden rule...do unto yourself as you want others to do unto you.