Don’t panic. Don’t “throw in the towel” or worse yet throw away your towel because then you would have nothing, nothing that is to wipe the sweat from your face and hands.
Go to your “happy place” to that imaginary place in your mind where there are “trees and flowers and chirping birds and basket weavers who sit and smile and twiddle their thumbs and toes…” Then again, maybe that is not such a good idea.
Be positive. Use positive affirmations and “self talk” to motivate yourself and to get yourself back on track. From personal experience, a little fist pump followed by a “let’s go” or “come on” works better than a whack in the shins with your racquet (very painful).
Take a deep breath and refocus your energy to playing one point (not two or three points) at a time.
Acknowledge you’re having a hard time with your composure, your game, your opponent, etc. Acknowledgement is the first step to dealing with your problems. The best way to overcome an obstacle is to confront it head on. Don’t offer yourself any excuses, anything that mentally gives you an “out” or a reason not to perform or do your best.
Stay in the present. Don’t dwell on your past mistakes, missed opportunities or bad turn of events. Deal with the bad bounces, unlucky breaks, etc. by “moving forward and putting things behind you”.
Generally it is best to slow things down if you are losing your composure. Judiciously take more time between points (up to 20 seconds between points) and during changeovers (up to 90 seconds). A towel break (assuming you still have your towel) is a good way to buy time between points. Be conscientious of how you are managing the time and tempo of the match. If the points are ending too soon, get more balls in play and try to lengthen the time of each point. If the rallies are too extended and the points are taking too long to develop, try to take time away from your opponent and shorten the length of each point.
Be very deliberate prior to hitting your first and second serves and prior to receiving each serve from your opponent. Establish or re-establish a ritual prior to serving and receiving to eliminate outside distractions and to narrow your focus to the task at hand.
Consult your inspirational reader (conveniently placed in your racquet bag along with your back-up towel) during the changeovers. For more profound inspiration and direction refer to something like the Art of War. Another option is the Oh, the Places You’ll Go! by Dr. Seuss. “I’m sorry to say so but sadly, it’s true that Bang-ups and Hang-ups can happen to you…”
Put things back in perspective and remember what it is you enjoy about hitting tennis balls and getting on the court to compete.