Positive self statements can make you feel worse...try rewiring instead...

"Their study, entitled “Positive Self-Statements: Power for Some, Peril for Others,” ... showed that people with low self-esteem actually feel worse after repeating positive self-statements such as “I am a lovable person” or “I will succeed.” Rather than being helpful, these positive thoughts typically triggered a strong negative reaction and a resultant low mood."

Read further from this article: This Is How To Rewire Your Brain For Happiness.