never thought that as a hard rock fan I would submit a tab for
Johnny Cash! but here we are for a beautiful cover version:

I wont waste time with the verse tab as most others have
got it...except, instead of a major 'D' chord try 'Dsus2' which
looks like this:

e --------0----- (OPEN STRING)
B --------3-----
G -----2--------
D --0-----------
A --------------
E --------------    The rest is around Am and C as others have

For the chorus its..........

e ---3---------3--------3---------3----------
B ---3---------3--------1---------1----------
G ---0---------2--------2---------0----------
D ---0---------2--------3---------2----------
A ---2---------0--------X---------3----------
E ---3---------X--------X---------X----------
    G      A7sus4      Fadd9     C (with an extra
                                    5th 'G' thrown in)

So....

Am/C/Dsus2/Am/C/Dsus2/Am        C        Dsus2  Am
Intro........................   I hurt myself today  etc...

At end of verse

    C            Dsus2    G  (begining of chord sequence)
...I remember everything......

A7sus4        Fadd9 C           G
What have I become, my sweetest friend etc...

....then last line of chorus

A7sus4     Fadd9       C             Am   C(back to the Am C Dsus2 phrase)
I will let you down, I will make you hurt...

Am C Dsus2 etc etc


Listen to the rythm of the song and you 'll here how it moves easily
through this sequence of chords - build the sound from quiet to get
that emotive feel to the chorus.  End on the 'C' at the very end and let
it ring out.  One the most painful songs and videos I have ever heard
or seen.  God knows how many people see it and think 'yeah, thats me..'