I feel as though your opening post could have been written by me. I found myself in your same position this Christmas. Had to take a "job for the man" after being my own boss for a lengthy period. I felt unsatisfied and was getting increasingly unhappy. It was affecting me and my family negatively. It was really crappy but lit that fire under my a to change my story
I got out of the "job" and went back into business for myself!
I know you posted start up costs are prohibitive, but you MUST find a way. It may be hard and challenging and frustrating, but MAKE IT WORK!! Live and die by it and all
When you work for yourself, doing what you love, you'll NEVER "work" a day in your life!
Best of luck!! You can do it!!!