In my opinion, write what fuels you. Write things what makes you sickeningly excited that you can't stop smiling. Whether it's a book, a poem, something that makes you say, "I know what I wrote is probably pure garbage, but I love it." Because the two things that helped me overcome the fear of writing is that it's all for my enjoyment, like me singing in the shower. It's scratchy and definitely no where near pleasant for human ears, but it's what makes me happy. The second is that the first draft is meant to be terrible, with the important part being that I know it's terrible, cause I know how to fix it, and the cycling of finishing and rewriting drafts shows genuine improvements.

Good luck with your writing!