Every thought has the power to push us to act a certain way. For example, if you believe you do not have what it takes to achieve your goals, you will not take the necessary action to make your goals a reality. If you believe that you do in fact have what it takes to achieve your goals, you are said to have self-efficacy. People with self-efficacy tend to take whatever action is necessary to achieve goals, regardless of fear. Fear of failure will not stop someone who has self-efficacy. Repeated action leads to habits, which then make it easier to take valued action in the future, which is aligned with their goals. This forms your character, which then influences your destiny.
Antidote: The antidote to being a slave to your thoughts is to train in mindfulness, which allows you to view your thoughts for what they are—nothing by insubstantial mental constructs. Then you will have greater choice in your ability to act or not to act on your thoughts.