This is how I play this and all the words are correct. These chords work for me.

The G I use is played adding the 3rd fret of the B string and using the
pinky to play the high e. I don't know the exact name, it's just shown as G on the 
chord charts I could find, 

G (W/D) is a walk down from the G to the Em


G (320003@1)                DI (xx0232@1)pretend that I'm glad you went away,
Em (022000@1)                  DAnd (xx0232@1)these four wall's close in more everyday
        Cadd9 (x32030@1)          D (xx0232@1)                 G (320003@1)     DAnd (xx0232@1)I'm dyin inside, and nobody knows it but me.

G (320003@1)            DLike (xx0232@1)a clown I put on a show,
Em (022000@1)                     DThe (xx0232@1)pain is real even if nobody knows
        Cadd9 (x32030@1)           D (xx0232@1)                 G(W/D) (320003@1)And I'm cryin inside, and nobody knows it but me.

Em (022000@1)                 DWhy (xx0232@1)didn't I say the things I needed to say,
Cadd9 (x32030@1)            DHow (xx0232@1)could I let my angel get away.
Em (022000@1)                    DNow (xx0232@1)my world is just a, tumbling down,
Cadd9 (x32030@1)                  Cadd9I (x32030@1)can see it so clearly, that your nowhere around.

CHORUS:

G (320003@1)                          DThe (xx0232@1)nights are so lonely the days are so sad, and
Em (022000@1)                          DI (xx0232@1)just keep thinkin about the love that we had
        Em (022000@1)            Cadd9 (x32030@1)             GAnd (320003@1)I'm missin you, and nobody knows it but me

Interlude: G D Em D Em Cadd9 G (W/D)

Em (022000@1)                    DHow (xx0232@1)blue can I get, you can ask my heart
Cadd9 (x32030@1)                             D (xx0232@1)   
Just like a jigsaw puzzle it's been torn all apart
          Em (022000@1)                DA (xx0232@1)million words couldn't say, just how I feel
Cadd9 (x32030@1)                            Cadd9A (x32030@1)million years from now you know, I'll be lovin you still

Repeat Chorus