@cor17 As you have found, healing from TBI is hard and very slow. I didn't have physical injuries beyond my TBI and skull fracture. Physical injury adds to the fatigue. After 2 years I felt better, but still some physical and emotional fatigue. I exercised my brain and body when I wasn't fantasizing about naps. I still had to heal from the social isolation; every time a coworker joked about me being brain damaged I felt gut punched. Most people will have no idea of what you are going through physically and emotionally, and having at least one person for support is important. I was also working on integrating who I was with who I was now; even just having a TBI will change you for better and worse. I lost trust in my self and abilities until I had healed enough to recognize what a difficult journey I had been traveled.
Most of my recovery took about 2.5 years (as marked by smell and taste returning and word finding mostly returning). It actually took more than 8 years for my final-point recovery, when my left temporal EEG was normal and driving felt like cars were not aiming for me (processing incoming noise, motion, colors). It has been 33 years, and my word finding didn't recover completely, but it means I have a good excuse to cheat on crossword puzzles.