This is the first tab i have posted on the internet so hopefully it is correct.
Here goes...

The guitar part throughout the verse is a B5/f# chord played with the following strumming pattern:

    B5/f#
E:|-----------------------|
B:|-----------------------|
G:|--4-4-x-4-44--xx--x-x--|
D:|--4-4-x-4-44--xx--x-x--|
A:|--2-2-x-2-22--xx--x-x--|
E:|--2-2-x-2-22--xx--x-x--|

Intro: B5/f#

Verse:

B5/f# (as above)
now i will tell you what i've done for you
50 thousand tears i've cried
screaming deceiving and bleeding for you
and you still won't hear me
don't want your hand this time i'll save myself
maybe i'll wake up for once
not tormented daily defeated by you
just when i thought i'd reached the bottom

G  A    Em    
i'm..  dying again


Chorus:

          Bm   G    D    A      Bm   G   D
i'm going under..    drowning in you
       A     Bm    G    D       A      Bm      G    
i'm falling forever..    i've got to break through
  D      A
i'm going under    .....ends with the B5


Verse:

B5/f# (as above)
blurring and stirring the truth and the lies
so i don't know what's real and what's not
always confusing the thoughts in my head
so i can't trust myself anymore

G  A    Em    
i'm..  dying again


Chorus:

          Bm   G    D    A      Bm   G   D
i'm going under..    drowning in you
       A     Bm    G    D       A      Bm      G    
i'm falling forever..    i've got to break through
  D   A
I......


Bridge:

             G                 F#                Bm
so go on and scream, scream at me i'm so far away
       Bm/A (x04432)    G
i won't be broken again
            F#
i've got to breathe i can't keep...


Chorus:

      Bm   G    D    A      Bm   G   D
going under..    drowning in you
       A     Bm    G    D       A      Bm      G    
i'm falling forever..    i've got to break through
  D      A
i'm going under     ........Song ends with one run through of the B5/f#.