I don't know about just starting a blog for personal interest, but I can tell you that you can make money online only. I left a CFO job when the CEO made it clear that I was expected to do something illegal. We mutually agreed to part ways, and I was forced into doing my own thing without any preparation. I found that I could get paid $35-$100 per article/blog on fairly interesting subjects. What I learned was that having a niche (in my case, healthcare IT, revenue cycle, medical writing, or healthcare administration) pays very well for freelance writing. (If you want to write about makeup or fashion or recipes, then you can expect to compete with people charging $0.05 for an hour of work). I used freelance sites and built a portfolio, and now I get $45-100 per blog. To start out and build my portfolio, I charged $20-25/hr. If you have credentials like a masters degree, it helps.
This is decent part time income for blogging. My suggestion is to write for someone else and see if you develop a following. If you have a specialization, all the better for having income. I hear you on working for the man.