You are right about the difficulties of freelance writing, but you can make enough money to quit your corporate job. It takes awhile to build up those private clients, but after a year, I make above 50k a year. I can see the potential to make far more, but I am working as hard as I want to to work. I only say that to be encouraging--if it is your goal to freelance full-time, it is doable. Good luck.