Here’s an encouraging article for writers via HuffPost:
New Authors, Fret Not. Most Successful Authors Made Their Mark After 30
The headline sums it up but if this topic interests you it’s worth checking out the attached infographic. It allows you to highlight author age at first published book, at their “breakthrough” book, and also shows a nice timeline of the number of books published before and after death. J.R.R. Tolkien was 46 when The Hobbit was published (also, Nora Roberts is a publishing machine, and I mean that in the best possible way).
So fret not, and keep at it. Because writing well is a skill, and skills take time.