I agree with the other two, and think you need to dig deep to discover your writing ambitions, and then decide on your path.
I try and look at it optimistically. J.K Rowling wrote exactly what she wanted after her first two novels didn't sell, and now she has £500 million, which is about $1000 million, which I believe Americans class as billion, but we don't.
Now she has the luxury of writing when she wants, but if you're starting out and really want it to be your career, you'll have to put the hours in.
Although, if Harry Potter hadn't sold, she still be working a nine to five, so IMO the best thing is to find a job you can live with, something that gives you experiences you can use in your writing, and maybe you will have a great book in you and be able to write for your career, or maybe not. Just don't spend years bitterly doing something you hate waiting for the day your work sells. Life happens all the time, not just when your dreams have come true.
Good luck.