Our minds are at constant work. There is an inner dialog running most of the time and most of it is critical. It takes conscious effort to stop and listen to the chatter and then an even more focused intention to question what is being said as TRUTH. The dialog occurs on autopilot. The neuro-pathways are laid down and then wear a track in our unconscious, like water through sandstone. In this trance- like state we become hypnotized believing the story that is created about ourselves, life, and those around us.
There is an abundance of techniques and models proposed to try to stop this mental tirade and even to turn it around. (i.e. CBT, narrative techniques, mindfulness, The Work to name a few).
Remember, those who are giving you advice have their own inner dialogs.
Think about times and events in your life where you were successful? Did you follow your own instincts or the advice of others.
Start trusting yourself on small stuff and watch what grows.
Read biographies of people you admire. Most likely they were told at one point in their lives they would not be successful at the very thing for which you admire them.
You can bet on the house, because you are the house.
Trusting your own thoughts and beliefs and acting on them can be scary. People around you may not agree or even like your decisions. Ultimately, though, you are accountable to you and at the end of the day the only person you have to please is you.
Whether you think you can or think you can't - you are right. ~Henry Ford