This is a very complex situation indeed. You need to reorganize & structure each area of focus to start. Quick advice is not the answer. His brain injury is an ongoing impediment to your respective Union but he must start to realize triggers/negative history repeating.
As the two of you go forward it’s always going to be a “reset” button that sets you both back further each time. Sit down with him in a calm moment, map out new ways to strategize where/when/how being proactive with healthier & positive reactions will establish constructive patterns of behavior as opposed to negative/toxic/destructive reactions that shut down communication.
