I know nothing about the lifestyle you support, but providing yourself with the basic & bare essentials might be possible if you write for "several sites," & schedule yourself for at least 12 hours/day X 7 days. That schedule might get lighter after you are well established & experiencing success.
This is what a few full-time writers, having done this for some time now, have disclosed when responding to similar questions.
I will hope that some of our fellow writers here on HP who have been able to make their living online writing, will reply to you with detailed & helpful info. I understand there are long term writers here who have had success and I also know it is not easy. Commitment & tenacity! Good Luck.