Turning hobby into business and building business out of hobby are two different concepts. I have started with the first. Failed dramatically and through this failure learned how to do the second.
Focus on building a business rather than doing your hobby. Most people I know who turned their hobby into business ended up enslaved by their hobby, ended up creating a job for themselves rather than a business which can be sold. Most hobbies don’t last longer than 7 years. Businesses do.