So heress the easiest and probably the rightest way to play this song.
Hope you enjoy it!

Am   Bbm  C   C#  G   Dm  Ebm 
-x-  -x- -x- -x- -x- -x- -x-
-1-  -0- -1- -3- -0- -3- -3-
-2-  -2- -0- -0- -0- -2- -0-
-2-  -2- -2- -2- -0- -0- -0-
-0-  -0- -3- -3- -0- -0- -0-
-0-  -0- -0- -0- -2- -0- -0-
-x-  -x- -x- -x- -x- -x- -x-

(note : Am# C# and Dm# are called here "intermediate chords")

Prelude : (every written chord is one string play from up to down).
Am  Am  Am  Am  Am  Am  Bbm  Bbm 
C   C   C   C   C   C   C#   C#
G   G   G   G   G   G   G    G
Dm Dm  Dm  Dm  Ebm Ebm  Dm  Dm

Dm      Am
In this farewell
           C
Theres no blood
           G
Theres no alibi
Dm                Am
Cause I ve drawn regret
         C
From the truth
     G
Of a thousand lies


[Pre-Chorus]
Dm           Am
So let mercy come
   C      G
And wash away
Dm        Am     Bbm
What I ve done

[Chorus](with the "intermediate" chords)
     C          C#
I ll face myself
G                 Dm Ebm Am   Bbm
To cross out what i ve become
C          C#
Erase myself
G             Dm  Ebm   Am
And let go of what i ve done

C 
Put to rest
         G
What you thought of me
Dm                 Am
While I clean this slate
         C          G
With the hands of uncertainty

[Pre-Chorus]

[Chorus]

For what I ve done
I start again
And whatever pain may come
Today this ends
I m forgiving what I ve done!!!

[Chorus]

What I ve done
Forgiving what I ve done