Open Eyes made a remark that helped me realize that anger is one of the triggers for my deep seated guilt feelings.

I seldom let my anger show. hardly ever let anyone know just how mad I am or that the rage is just under the skin. i've trained myself to show no anger like that.

But when the anger does surface, when i let it out for others to see, it triggers a feeling of guilt for several days. the last time I did this i felt so guilty for about a week afterwards. It wasn't so much a guilt of having been angry as it was a vague feeling of guilt about my whole life.

Maybe this is why I bury the anger so often