Tommy,
It does suck. Unfortunately, it takes a very long time for the brain to recuperate. From a year to years - survivors slowly regain strength and acceptance. You being a boxer is not good at all for recovery. You may completely receover. A big negative is the fact that those with TBI's are likely to get more TBI's. We get clumsy and often fall. While the first one or two head injuries may seem relatively minimal, they do have a marked effect.
I hope that you do feel better soon! No nausea, panic, and dizziness: it's no fun! Be good to yourself...don't get back into the ring. Have you checked that magazine, written by doctors, called Neurology Now? It's free. You can check them out online, and read past articles. One article regarding recurrent concussions w/ sports (I think they focused on football) was amazing! Please do check out the site. The articles can be informative and enlightening.
http://www.neurologynow.com
Best wishes, take care!
Shez