Here are a few resources on burnout.

Articles

Helping Senior Pastors Overcome Depression and Burnout: Written to help pastors specifically, but has so many good insights both theologically and practically for overcoming burnout.

How I Recovered From Burnout: 12 Keys to Getting Back: Short article written from ministry/Christian perspective.

Why Do We Work Too Much?: Good, practical thoughts on reducing work load. Too much to do contributes greatly to burnout.

Books

Can’t Even: How Millennials Became the Burn Out Generation by Anne Helen Petersen: