because of the overwhelming demands and random priority changes that expect you work beyond scheduled hours.
Bootstrapping your own thing will give you more of that, not less. It takes an established business to be stabile to the point where the surprises are minimal, the processes are standardized, and the team is built to absorb whatever is thrown at it to handle things without putting in extra hours.
It sounds like you need to find established companies who need some part-time help.