You can earn money with a writing career, of course. But it takes talent, work, and time. You have to really learn the craft. There is an element of luck. Networking helps. Being in the right place at the right time to pitch an idea to an editor or agent can help. Eventually, if you do everything right, you can make a living at it.
Unfortunately, bills do not wait for "eventually." So tonight, working for money trumps writing.