You captured the fear and the self doubt quite admirably but I have no idea what the protagonist is up against. I’ve had similar conversations with myself.

13 can paralyse the greatest man ( or woman)
You are very brave to poke the stick at this number! Carry on.

At first I was disappointed that there wasn’t a “pay off” at the end in terms of what exactly this person is hesitating to do. After reading it though, I like that. It leaves it more applicable to any reader, any situation.