I've been told by numerous professionals (and I've read the same thing in many articles) that the people who are "Type-A Personalities", stubborn, very motivated and/or over-achievers have the BEST recoveries. Just try to stick through it as best you can and hang onto that hope.
Just the other day, I spoke to a researcher who's worked with more than 500 TBI patients in the last three years and he said that the people who tell themselves, "this is unacceptable" make the best recoveries.
I think the same thing that makes us overdo it, is what pushes us toward our eventual successes.
Don't worry when you get down in the dumps or scared... it's completely natural. Something might be wrong with you if you didn't experience those things.

But pick yourself up from that as soon as you can and keep on truckin'!