Writing personal stories always feels like narcissism, and I'm very unsure if I'm ever creating anything of value with it.

I'm going to narcicassate myself by indicating I agree. My senior year of high school we did a Memory Book project where we gather photos of trips and write essays about our lives thus far. Mine was mostly just essays because not many photos of me exist. I ended up with a C because I cut up all the family photos of me that my parents had and went through all the pics my friends owned as well and only had enough photos for half a book.