My oldest did that last year CW. Remember? It was so bad he would pass out right before his matches. We couldn't figure out what his deal was until we sat him down and asked. He told us he didn't want to disappoint us so we pulled him out for the rest of the year and he came back this year strong and ready to go! Mom and Dad though had to remember to comfort him win or lose let him know we are proud of him and stop telling him all the time what he was doing wrong. Sometimes I wish there was a book to tell us how to handle this but there isn't. Tell your little one to hang in there.