Hi Jeremy and welcome to PC

When you first notice this happening, try to slow it down so you can see where it begins. What are you thinking about? What are you feeling? Are your thoughts and feelings something you allow, or something you push away/deny/disavow?
You might notice that when this begins, you are thinking about something that makes you feel angry and you don't want to feel angry or you don't want to have the thought so the anger becomes something from outside of you...rather than from inside of you.
Allowing the experience of anger is too frightening for some people. It can feel less threatening if it is anger coming from outside of you, so your mind does that for you as a self-protection.

Do you have a psychotherapist who can explore these kinds of experiences with you?