As you've probably already gathered, every concussion experience is unique. There is really no way to know who will recover, how quickly and how completely.

I never did regain the "old me" - but my TBI was severe.

A hopeful sign I see in your case is that, even at this early stage, you are aware that there is a difference between your pre and post TBI behaviour. Really badly injured people tend to be completely oblivious to their issues, even when they're leading to behaviours as extreme as acts of physical violence and rampant promiscuity.