Remember also that every author who has managed to make a living off of their writing took time to get there. You aren’t likely to be able to quit your day job after the first book, or even the third. But keep working, keep producing quality content, treat it like a business and learn the market. You can greatly improve your chances. Self-Published means you aren’t just a writer, you are a marketer, a publisher, etc.
I want to be able to make a living off of my writing too, so I understand where you’re coming from. To get anywhere, I realized that I’m going to have to sacrafice a lot now in the hope’s for it to pay off later. It means I have to use a lot of my spare time to write, learn the market, learn about self publishing while I work full time. I have to save my allowance now and tuck it aside. It means working seven hour days then writing another three hours after. It means making connections, learning from others…but this community is a good community. Friendly, encouraging: they’ll give the hard truths sometimes but they are the truths you need. They want you to succeed.
Might I suggest, if this is your passion, to also look at other income sources for writing? If you’re a fast and disciplined writer, ghost writing can be a more guaranteed income to help you along.