I think these are fairly accurate chords, comment if you've got any corrections.

Capo on 3rd fret

Em  C  G  D/F#

Verse 1:

Em
When I'm nervous I have this
C
thing yeah I talk too much
G
Sometimes I just can't
D/F#
shut the hell up
Em
It's like I need to tell 
        C
someone anyone who'll listen
                   G
And that's where I seem to fuck up, yeah
                   D/F#
I forget about the consequences, for a minute there I lose my senses
                              Em
And in the heat of the moment my mouth's starts going the words start flowing
Em
But I never meant to hurt you,
                               C
I know it's time that I learnt to
                        G
Treat the people I love like I wanna be loved
     D/F#
This is a lesson learnt,

Chorus;

Em
I hate that I let you down 
C
and I feel so bad about it
G
I guess karma comes back around
D/F#                            (optional) D
cause now I'm the one that's hurting yeah
Em
And I hate that I made you think 
C
that the trust we had is broken
G
So don't tell me you can't forgive me
D/F#
Cause nobody's perfect, no.
Em                   C        G        D/F#
no no no no no no no no no no no no no no no no

Em
If I could turn back the hands of time 
C
I swear I never woulda crossed that line
G                                    D/F#
I should have kept it between us but no I went and told the whole world how Im feelin ah 
Em             C                                      G
So I sit and I realize  with these tears fall from my eyes
D/F#
I gotta change if I wanna keep you forever I promise that Im gonna try

Em
But I never meant to hurt you,
                               C
I know it's time that I learnt to
                        G
Treat the people I love like I wanna be loved
     D/F#
This is a lesson learnt,

Em
I hate that I let you down 
C
and I feel so bad about it
G
I guess karma comes back around
D/F#                            (optional) D
cause now I'm the one that's hurting yeah
Em
And I hate that I made you think 
C
that the trust we had is broken
G
So don't tell me you can't forgive me
D/F#
Cause nobody's perfect, no.
Em                   C        G        D/F#
no no no no no no no no no no no no no no no no

Em, C, G, D

Em                             C
Im not a saint not at all what I did that wasnt cool
                 G               D/F#
Imma swear that Ill never do it again to you
Em                               C
Im not a saint no not at all but what I did wasn't cool

Em
I hate that I let you down 
C
and I feel so bad about it
G
I guess karma comes back around
D/F#                            (optional) D
cause now I'm the one that's hurting yeah
Em
And I hate that I made you think 
C
that the trust we had is broken
G
So don't tell me you can't forgive me
D/F#
Cause nobody's perfect, no.
Em                   C        G        D/F#
no no no no no no no no no no no no no no no no

Em
I hate that I let you down 
C
and I feel so bad about it
G
I guess karma comes back around
D/F#                            (optional) D
cause now I'm the one that's hurting yeah
Em
And I hate that I made you think 
C
that the trust we had is broken
G
So don't tell me you can't forgive me
D/F#
Cause nobody's perfect, no.
Em                   C        G        D/F#
no no no no no no no no no no no no no no no no