Feelings of fear and doubt are not evidence that you are not brave. They are just feelings. And feelings are not always facts.
Every brave person who ever did something meaningful did it while feeling scared. The fear was there. They moved forward anyway. That is exactly what courage is.
You have done hard things before. You have faced uncertainty and gotten through it. You have shown up on days when showing up was the hardest thing imaginable.
That is bravery. It lives in you already. You just have to remind yourself it is there.