Need help redirecting my brain

Oh, my goodness!
My kids started school today and I hit the ground running with my business.
I ran straight into the thought “I don’t know what I’m doing”
“Other people are doing the same thing, why are you going to make it if they haven’t already?

I guess a long time ago I bought into the idea that there is only a limited amount of success in the world.
And I’m learning that this is not true.

Help me redirect my brain.