This song is fairly straightforward - I've transcribed the chords for a single 
acoustic (or rhythmn) guitar. The C-C4 Am-Am6 G progression is played as 
follows - you'll have to get the timings by ear (probably the trickiest bit):

      C     C4      A     Am6        G (2 bars)
e | ----0-0-0-0-0--- | ----0-0-0-0-0--- | ----3-3-3-3-3-3-3-
B | ----1-1-1-1-1--- | ----1-1-1-1-1--- | ----0-0-0-0-0-0-0-
G | ----0-0-0-0-0--- | ----2-2-2-2-2--- | ----0-0-0-0-0-0-0-
D | ----2-2-2-3-2--- | ----2-2-2-3-2--- | ----0-0-0-0-0-0-0-
A | ----3-3-3-3-3--- | ----0-0-0-0-0--- | ----2-2-2-2-2-2-2-
E | ---------------- | ---------------- | ----3-3-3-3-3-3-3-etc


Intro: C Em Am F

Verse 1:

C
 The last time you walked away
                              Em
You left this weight with me,

It's in my heart it's on my back,
                         F
I think it might bury me,

I wanna cast you out,
                           G
But that's just half of me,
                                                        C - C4
The other half believes there's more to us than tragedy,


Bridge:

Am - Am6   G
But I can't do it on my own


Chorus:

C         Em       Am
Oh, oh oh oh, oh oh oh,
       F
Stay, stay, stay,
C         Em       Am
Oh, oh oh oh, oh oh oh,
              F
Or don't come back if you walk away,
C         Em       Am
Oh, oh oh oh, oh oh oh,
           F
I can't go on like it's all the same,
C         Em       Am
Oh, oh oh oh, oh oh oh,
         F
So stay, stay stay.


Verse 2:

C
  Don't tell me you're not safe,
                            Em
It sounds like a dare to me,
                                                          F
And if you doubt don't shut me out, that's not fair to me,
                                                        G
I know i hurt you too, When I was looking for clarity,
                                                        C - C4
But all I know is when I go, I want you there with me.


Am - Am6   G                 C - C4
'Cause I can't do it on my own,
Am - Am6     G                                        C
And if I got you I think I could hold on, hold on...


Chorus:

C         Em       Am
Oh, oh oh oh, oh oh oh,
       F
Stay, stay, stay,
C         Em       Am
Oh, oh oh oh, oh oh oh,
              F
Or don't come back if you walk away,
C         Em       Am
Oh, oh oh oh, oh oh oh,
           F
I can't go on like it's all the same,
C         Em       Am
Oh, oh oh oh, oh oh oh,
         F
So stay, stay stay.


Solo:
D Am D Am D Am F C


Bridge:

C - C4 Am - Am6 G    C - C4

Am - Am6   G                 
'Cause I can't do it on my own,
C~~
Oh, oh oh oh, oh oh oh,

No-oh-oh-oh

Oh, oh oh oh, oh oh oh,

Or don't come back baby


Chorus:

C         Em       Am
Oh, oh oh oh, oh oh oh,
       F
Stay, stay, stay,
C         Em       Am
Oh, oh oh oh, oh oh oh,
              F
Or don't come back if you walk away,
C         Em       Am
Oh, oh oh oh, oh oh oh,
           F
I can't go on like it's all the same,
C         Em       Am
Oh, oh oh oh, oh oh oh,
         F
So stay, stay stay.

Outro:
C Em Am


Enjoy!