You searched for: “graphophobia
graphophobia (s) (noun) (no plural)
A pathological and extreme aversion of writing: Arno wasn't very good in school, especially in English and suffered from graphophobia, and he avoided jotting down anything, even a shopping list or his signature while others were looking!

This may be a result of a fear of criticism of one's penmanship and misspellings, as well as a fear of committing ideas to paper for others to see.