Are you a winner?

Yesterday I got smashed on the tennis courts. Not just beat; slaughtered. Mincemeat.
Was my opponent good? Yeah. Was she better than me? Maybe, but on a good day I could take her, or at least put up a decent fight.
So what happened?
Well...let's go back to an hour before the match. I'm dissed by someone close to me. I feel like the wind is knocked out of me and the hour traveling to the match and the fifteen minute warm-up do nothing to dissipate my feelings of unworthiness.
Now I know I was the same person then that I was an hour earlier. Before the 'diss', I had a good chance of winning and continuing on through the tournament. After the 'diss', there was no chance. Mentally, I had confidence in my abilities, but emotionally I could not convince myself that I am a decent player and had an excellent chance of winning the match.
I swore then and there that I would do what makes me happy at all times and never would I let someone else's perception of me affect a sporting event that I love.
But how?!
I've been working on this for quite a while, for the short version check out my next blog, four ways to feel what you know to be true.