I quit my job and started freelancing in 2011. I'm glad I did, but it's not easy. I work for magazines. There are lots in the USA. Do you have a particular hobby or niche you could write about? That could be a way into a niche title. Or helping marketing agencies with their work? I hope you find it works for you. It's not easy. I spent 10 days pitching 7 days a week for a fortnight before I got my first freelance job, following shortly after by a second.