For me burnout is more personal than a work issue. I worked long hours, but when I stopped I burned out even more on life and people challenges.
I struggle with all sorts of issue about taking downtime. Even when I have a routine in place of taking time out to exercise or to care for myself, I seem to have issues all round about.... not giving myself away to friends, and to people generally. Even though I have good boundaries. It's easier to give myself away than to deal with the pain/ fear/ self-hatred inside - and when I deal I just cry which seems stupid really.
Probably it's a pattern of restlessness created because no one in my family valued me for me, or even valued themselves for them. An inherited distress pattern.