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):

      C5     C5      A5     A5        G5 (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: C5 E5 A5 F5

Verse 1:

C5
 The last time you walked away
                              E5
You left this weight with me,

It's in my heart it's on my back,
                         F5
I think it might bury me,

I wanna cast you out,
                           G5
But that's just half of me,
                                                        C5 - C5
The other half believes there's more to us than tragedy,


Bridge:

A5 - A5   G5
But I can't do it on my own


Chorus:

C5         E5       A5
Oh, oh oh oh, oh oh oh,
       F5
Stay, stay, stay,
C5         E5       A5
Oh, oh oh oh, oh oh oh,
              F5
Or don't come back if you walk away,
C5         E5       A5
Oh, oh oh oh, oh oh oh,
           F5
I can't go on like it's all the same,
C5         E5       A5
Oh, oh oh oh, oh oh oh,
         F5
So stay, stay stay.


Verse 2:

C5
  Don't tell me you're not safe,
                            E5
It sounds like a dare to me,
                                                          F5
And if you doubt don't shut me out, that's not fair to me,
                                                        G5
I know i hurt you too, When I was looking for clarity,
                                                        C5 - C5
But all I know is when I go, I want you there with me.


A5 - A5   G5                 C5 - C5
'Cause I can't do it on my own,
A5 - A5     G5                                        C5
And if I got you I think I could hold on, hold on...


Chorus:

C5         E5       A5
Oh, oh oh oh, oh oh oh,
       F5
Stay, stay, stay,
C5         E5       A5
Oh, oh oh oh, oh oh oh,
              F5
Or don't come back if you walk away,
C5         E5       A5
Oh, oh oh oh, oh oh oh,
           F5
I can't go on like it's all the same,
C5         E5       A5
Oh, oh oh oh, oh oh oh,
         F5
So stay, stay stay.


Solo:
D5 A5 D5 A5 D5 A5 F5 C5


Bridge:

C5 - C5 A5 - A5 G5    C5 - C5

A5 - A5   G5                 
'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:

C5         E5       A5
Oh, oh oh oh, oh oh oh,
       F5
Stay, stay, stay,
C5         E5       A5
Oh, oh oh oh, oh oh oh,
              F5
Or don't come back if you walk away,
C5         E5       A5
Oh, oh oh oh, oh oh oh,
           F5
I can't go on like it's all the same,
C5         E5       A5
Oh, oh oh oh, oh oh oh,
         F5
So stay, stay stay.

Outro:
C5 E5 A5


Enjoy!