My TBI was 37 years ago (I'm 54 now). I have had problems with anger and self-control ever since, but I had no reason to link the injury to my anger issues. Until a couple years ago I began making threats to a former supervisor, and got dinged with a nice misdemeanor criminal threat charge. The incident did get me to turn focus on the accident and how it affected me mentally.

At this point, I would be surprised if most if not all of your symptoms were not connected to your brain injury.