Hello Phil Griffin: I see this is your first post here on PC. So... welcome to Psych Central.

You asked what might have caused the anger you felt for a few years to decrease over the past couple of months. I don't know as I have the answer you're looking for especially since you didn't mention what it was you were furious about to begin with. Yes, perhaps it is simply a matter of your anger having burned itself out over time. It is true, I believe, that time heals wounds. It doesn't necessarily take them away entirely at least based on my own experience. But lessens the sting. Or perhaps there are some good things that have been happening in your life & these good things have begun to outweigh the anger you carried for so long? I don't really know. These are just a couple of ideas that occur to me.

Here's a link to an article by our host Dr. John Grohol, Psy.D., from Psych Central's archives, on the subject of anger. The article provides links to a number of additional articles on the subject:

Anger Management | Psych Central

I hope you find PC to be of benefit.