Connor, have you considered that setting the bar at Mozart-level is maybe a teensy bit high? Just a tad? No one expects you to come out with a work of world-shattering genius next week. There's nothing wrong with Salieri. His Sinfonia in D major and his flute concerti are still being played, like in orchestras' upcoming concert seasons, according to my dear friend Google. Also, the play and movie Amadeus completely overdramatize the extent of the rivalry. The two composers were on perfectly cordial terms, and Salieri is not suspected of trying to kill Mozart, through fear of his dead father or any other means.
That out of the way, you absolutely will have to get a wage-slave job to pay the bills before writing can become a full-time gig. Ann Rule, the true-crime writer, just died with dozens of books to her name and a fairly massive group of fans, who kept in touch with her through her website. However, she started out staffing a crisis hotline and went on to become a Washington State cop before becoming a writing phenomenon. Real-world experience at anything, plucking chickens, answering fan mail for a celebrity, whatever, can only strengthen your writing. /tosses long optimistic speech out the window, knowing it will fall on deaf ears