When in doubt, don't.
When I consider the short duration of my life, swallowed up in the eternity before and after, the little space I fill, and even can see, engulfed in the infinite immensity of space of which I am ignorant, and which knows me not, I am frightened, and am astonished at being here rather than there, why now rather than then?
You have to persevere. You have to do it. I have insecurities. But whatever I'm insecure about I don't dissect it, but I'll go after it and say, What am I afraid of? I bet the average successful person can tell you they've failed so much more than they've had success. I've had far more failures than I've had successes. With every commercial I've gotten, there were 200 I didn't get. You have to go after what you're afraid of.