Burn out comes from a real or perceived gap between expectations and reality. That's the formula for shame. This gap can also lead to disenchantment, which is a lot like depression. When people believe they're not living up to expectations, everyday life events start to feel like bigger threats than they are or need to be. That causes anxiety - imagining you won't live up to expectations in the future. It can also then cause teachers to start to become short with students.
You can read about how to prevent or remedy "burn out" at a free website -essay writing service I've set up for fellow teachers.
1) To learn to have USA or Unconditional Self-Acceptance to combat the shame which turn can play out as anxiety and anger. It also helps to have UOA or Unconditional Other Acceptance for students. It helps temper our emotional responses to what they do that we don't like.
2) To learn to have an internal locus of control. Most teachers, like most people on the planet, have an external locus. They wrongly see what others say and do and what happens as being the cause of how they feel. That puts them at the mercy emotionally of other people, like students or administrators, and their life events. That typically causes them to feel worse than necessary or helpful, and to miss many opportunities to feel better, or less stressed. The reality is that it's really what we choose to think about such things that really causes how we feel. And we always have a host of cognitive choices that we alone can make. Learning this and reminding ourselves of it is extremely empowering.