the stress for me is getting out of bed in the morning end of 
Wot he said ⬆️
Look after your kit, keep on top of your books and know your limitations for work vs time. Business-wise my only stress is being able to fit my work into the time I allow for it.
I'd never go back to being an employee - targets to be met, deadlines, things that have to be done in order for someone else to get the rewards and credit; and all for someone else's business to reap the rewards of our work. Nah. Not for me.