I'm pretty sure these are the chords for You Lost Me from Christina's album 
Bionic. She performed this at the American Idol Finale.
If you have any questions, message me on YouTube: www.youtube.com/natman2005.

Am          Em
I am done, smoking gun
      F                C              E
We've lost it all, the love is gone
Am            Em
She has won. Now it's no fun
      F                C
We've lost it all, the love is gone

C
And we had magic
G
And this is tragic
Eaug                        F
You couldn't keep your hands to yourself

Chorus:
C       E                  F            Fm           
I feel like our world's been infected
C       E               F          Fm
And somehow you left me neglected
C       E            F             Fm
We found our life's been changed
F   Fm  C
Babe, you lost me

Am            Em
And we tried, oh how we cried
F                   C                 E
We lost ourselves, the love has died
Am                Em
And oh, we tried, you can't deny
F                        C             
We're left as shells, we lost the fight

C
And we had magic
G
And this is tragic
Eaug                    F
You couldn't keep your hands to yourself

Chorus:
C       E                  F            Fm           
I feel like our world's been infected
C       E               F          Fm
And somehow you left me neglected
C       E            F             Fm
We found our life's been changed
F   Fm  C
Babe, you lost me

Am              D                   Am
Now I know you're sorry and we were sweet
              D                     G
But you chose lust when you deceived me
             Eaug              F
You'll regret it but it's too late
                               C
How can I ever trust you again?

Chorus:
C       E                  F            Fm           
I feel like our world's been infected
C       E               F          Fm
And somehow you left me neglected
C       E            F             Fm
We found our life's been changed
F   Fm  C
Babe, you lost me

Enjoy!