I have no idea how this actually works, but for brainstorming purposes:
Is there a law school nearby? It sounds like you're good at what you do and have a ton of valuable experience but prefer working one-on-one or alone rather than with large groups. Maybe the school could put you in touch with students who need some tutoring or extra assistance? Maybe the school would even create a position and pay you to do this.
Are you looking to replace your entire income or for more of a hobby?
What are the best parts of your job--the parts you truly love and would miss--and can you figure out how to structure a practice to have more of that and less of the rest?
I'm a physician (and now life coach) and once we had our debt paid off and our annual expenses as low as we could, it gave me the confidence to bargain hard at work. Now I don't work overnights, holidays, or weekends unless I agree in advance as a special favor to a friend. I can also take as much unpaid vacation as I want. I'm not sure how it works in the legal field, but sometimes there are more options if you can think outside the box.