I read you're from the UK and it made me think of Mary Spender. She's a songwriter and performer that has been able to create an audience, I know of her from youtube. She talks often about her journey which should be relevant to your question.
Jacob Collier, who's from some other planet in that he has otherworld talent, he did it with youtube also.
Both of them have did on there own, i.e. no record company help.
Here's a clever way Mary got 650k views (and she now has 685k subscribers):
https://www.youtube.com/watch?v=-0iXupQUjWU