How do you deal with anger?

Delve into the root cause. Anger is always a secondary emotion. Anger occurs after we have judged something (or someone) as doing something negative. Once you can remove the judgement, you remove the anger. Recommend the book non-violent communication.

If the root is deeper, you might need an experiential therapy (like EMDR, trainspotting, or psychedelics) to get to the root.