What is OK?? and WTF is "FINE"?

My little brother Michael, is in the 172 stryker Brigade. These are the guys that were on their way home in August, after being in notheren Iraq for a year only to get new orders to turn around and go back in to Bagdad. He has been in Bagdad almost 2 months.
We got THE call yesterday, its the call that no one wants. "Michael has been hit, he's hurt"

What we now know is that he was hit by an IED (improv explosive device) He has head injuries. His skull is crushed and they will have to remove and replace 25% of it. The ARMY just keeps saying "he's fine, and in stable condition" what we learned today is "stable" just means that his heart is beating and he is breathing. Although we're still not sure what this whole "fine" thing is. He has been moved to Germany and is still nonresponsive, to sound. They say he's just sedated. But I dont know what to believe form the army right now.

Everyone Keeps asking me are you OK? and ya I guess, I mean I dont know what to do...I crying then I'm fine, then I'm back at crying all with in an hour. I don't know what to. I guess I've gotta just go on. I'll figure it out.