I looked at David's fingers on his live You Tube video of this song.  
Good tune, nice tele sound.
Gbar isn't a new kind of swimsuit but G barred at 3rd fret, or 334553.
Play around on Am to make it sound right.

HEAVY BREATHER
C
The walls of our house are thinner than paper 
    Em         G           C           Am
The roof is a vapor that hangs in the air 
C
And our wedding bed is made from the same stuff 
   Em        G       C     (hold)
Our bodies are made of 
Em(quick hit)
Chorus
C                                          Bm
If no heavy breath blew up these lungs
     Gbar                                   C
While dirt and wet spit hung a ghost in the air 
    D           C          D    G
We’re still here 

C                                            
While kids and their friends make war (or warm?) by the fire 
      Em      G             C           Am
Their old men retire to drink and do drugs 
C
We long for the truth We argue about it 
    Em          G             C          Am
But most of us doubt it will ever be found 

C                                Bm
So no heavy breath blew up these lungs 
                Gbar                       C
While dirt and wet spit hung a ghost in the air 
     D     C             Em
But we’re still here 
   D         G           Am
We’re still here…