If you're having to turn down work at a comfortably livable pay rate (considering additional taxes, health insurance, etc.) for lack of time, and this is an ongoing situation, not a one time fluke, then I agree it's likely you'll be able to do just fine going freelance full time. And if your current job is approaching the end of the line, it's probably a good time to make that jump. Not worth all the energy you'd have to invest in finding another job and getting up to speed only to quit N months later.