If you have the luxury, I'd suggest taking 6 months before venturing into something new if you go through a tumultuous time at work. (this is what I would have done in hindsight)
1-2 week(s) full detox - Somewhere beach'y' with no reception. Take a notebook and write about your thoughts, feelings, what went wrong, what questions were left unanswered, what you could do better next time and re-evaluate what you love and your values.
2-4 weeks fun - ...
1 month discovery - Get back home and organise to meet all of the most interesting people you know to start to find opportunities that interest you, spend a lot of time walking and reading in this period.
2 months planning - Choose 2-3 of those opportunities that really make you excited and begin a typical discovery process for a new business/idea. Such as speaking to customers, researching competition, finding experts in that field to learn from.
2 months lead into new thing - Decide on the thing you want to pursue and actually begin the project plan.
P.s all of my posts are first drafts, my researcher will buff them out — so make sure to write in and ask for extensions or explanations if you are interested. Also, I write the way I speak - I don't particularly care for detailed grammar etc. I don't understand peoples obsession with it.