Believing I can actually make great money independently

I am sometimes really believing in myself and my ability to make great money doing what I love. I have other moments where I really question whether it’s really possible to make 100,000 a year, 1,000,000 a year etc? It just seems like such a huge jump for me from making not more than 1,000 a month. However, I do believe I can, even though it’s also scary to think WOW, I COULD REALLY DO THIS? I wonder what teaching/tool/concept I can review and work on in order to help myself through this.