If you are anger because of something that happened in the past, that means you are still living in past.
Then how will you refrain yourself? Here are some tips:
- Dont hide your emotions. Convey to the person that their act is bothering you in non violent way
- Invest your emotion to do some constructive task such as gardening, jogging, etc. This process is called sublimation
- Try to live in present by realizing that the incident happened in past
- Do action against issue and ignore the person who made you angry. Eg.if you are angry because your teacher scolded you, try to ignore teacher and work on teacher student relationship and do some positive contribution. You can counsel students who suffer with same problem. You can arrange workshops to train teachers.