I don't know if anger could be considered a primary emotion or not. I'm not particularly well versed in the field of psychology. My understanding has been it is a sign, or symptom perhaps, of anxiety. But I certainly am thoroughly familiar with the feeling of anger. And I have not handled it very well either for the majority of my life. So I have some sense of what that's about.
I'm angry a lot of the time. But I don't tend to lose control like a used to. Part of that is old age. But, also, a while back I could see where my angry outbursts were hurting my spouse. And since I didn't seem to be able to control them myself, I went back to my former psychiatrist (I had been off all psych med's for several years) & got a prescription for Clonazepam which I now take. I'm on a pretty low dose. But it seems to help.