You are doing affirmations whether you know it or not. Affirmations are self-talk that affirms what you believe about yourself.
Now I don’t believe that you can completely flip the dial and do a 180 on your attitude but you can change it with the right language over time. I remember going to my first listing appointment and the whole time thinking, “I’m going to get nervous.” It didn’t happen because I knew the market inside and out. So it’s not instant magic but it does have some power.
If you want to know what you really think about yourself, pay attention to what you think or say when you make a mistake. And then pay attention when you win.
Now, if you want to change, start with affirmation that you believe to be true but scared to admit. Become that person because you are probably more of that great person than you expect.