What feeds it, and what to stop adding

The unglamorous list, and it is the most useful thing in the course.

Sleep. Short sleep lowers the threshold on everything, and if your nights are the problem then the honest next step is the course Nights that will not settle rather than more work on anger.

Pain, which people underrate badly. Three days of a bad back will do more to your temper than any insight will undo.

Hunger, and low blood sugar, and long gaps with nothing eaten. Heat. Alcohol or anything used to take the edge off, which removes the brake rather than the anger. And an unresolved argument left running in the background, which keeps the whole system warm for days.

None of this is the cause and none of it is the cure. It is the part you can change without needing to understand yourself better first.