Without sounding too cliché, much of the time, you have the power to improve your attitude to the situation you're in. Believe it or not, it's your decision whether you want to follow the norm and spend hours criticising yourself, or whether you're willing to go your own path and learn to love yourself. The first step is to stop mentally tearing yourself apart. Simply decide not to do it anymore, and check yourself when you accidentally slip up. You're the one in control.