​Want to quit my job and go back to running own business

For context: I’ve been working in my job for nearly 3 years. I absolutely hate everyone I work with, with the exception of one or two people.

I recently had a family emergency and the treatment I received from most of my team when I had to take time off has made me reconsider if I want to continue working there.

I have a Certificate in small business and have run my own small writing business previously. I’m also a trained teacher with many years of tertiary training experience.

I really want to go back to running my own business but the only thing I’m worried about is the money side. I have a partner that earns well but I don’t want to become a financial burden.

NOW to the ideas:

a college/school running nationally recognised certificates online (?) another content writing business (?)

Problem is my previous content writing business didn’t earn me very much, and while I’m good at what I do the experience has made me wary about dropping my current job to go back to what I was doing before. Also, finding clients was quite difficult – maybe Google ads or similar could help?

I think I’m just looking for a sounding board, thoughts, others’ experiences.