Plenty of anger

That is an old poem Written by Aldo Kraas

 There is plenty of anger inside of me
It has to stop
Why is there so much anger inside of me?
My anger is part of my frustration
I have to control it now
My anger causes me plenty of trouble
There is plenty of anger inside of me
And what is anger do I know?
Anger is a strong feeling of displasure
It is a grief that I have inside of me

How can I control it?

What triggers my anger?
Can I recognize it?