I completely understand everything that you have written and have had similar experiences. It really is awful. no two ways about it. I am 16 months past my injury and those electric brain shocks come less and less often. I can use a computer for longer, I have less headaches (although when they come they are bad!!), I have worked a bit more (academic work), I have exercised a bit (played some tennis!!), walked through DisneyWorld for a few hours with my kids, etc. So much progress...I felt little progress at one year but since then some good things.
No one knows where your recovery will sort of stop, but the brain in amazing and you need to believe in a great recovery. I try lots of different things, but it is difficult. neuro-opthamology is SO important, so if you haven't been checked, you should do that asap. I made huge progress when I got prisms in my glasses. Eyes that don't work together after a brain injury will ensure you never feel better.
I think my sense of smell is returning...so there is hope there!
I think what is so difficult but so necessary is to see progress in longer periods ....I have adopted 6 month chunks! And know that your brain will continue to heal as time goes by if you take care of yourself.
I am dying for a nice cold beer or a glass of red wine, a gin and tonic, but NOTHING since Sept. 11 2011.
Found some nice australian non alcoh wine

Day by day, and take care of yourself!