Honestly your jumping to conclusions instead of counting your self lucky that the worst that happened from the fall was a broken mirror..........breath!
Take a calming deep breath, the fright of falling and the shock of slamming head first into a mirror has likely still got your mind switched into fight or flight mode and running scared.......switch your focus on to all the positive of what happened....
Your not actually injured right if your saying you didn't loose consciousness at all, you sustained no cuts, no bruises, no swelling, no visual issues, no auditory issues.
You obviously didn't break a bone, your neck isn't stiff or painful to move, your not confused or struggling to communicate and you can't have a killer of a head ache either or you would of mentioned some type of damage you sustained.....breath!
....you walked away from a situation that could of done a lot of damage to you but you came out of it with no signs of having injured your self, which is the best out come anyone could of wished for!
Breath.........JJ