Welcome and well done on 3 months! You are right to be proud.
I'm a bit of an angry head too and I'm trying to observe it rather than act on it. This is a lot easier when I'm alone of course! It's an ongoing issue and I don't suppose I've got the solution just yet. What I have noticed though, is that's it's not as bad as it was a few months ago, so that's encouraging. Also when I can observe it, I've noticed the reasons (justifications) change, but the feelings are just the same, like the anger needs an outlet whatever the supposed cause. I think I'm coming to the same conclusion as Anna, I'm angry with myself.
Sorry to ramble, hope my experience is useful.
Good luck
xx