This is a depressing, yet great song. really  fun to sing and play.
I didn't see a correct tab anywhere, so here it is.
I was nice enough to include the exact times when the parts come in too.

INTRO:

(00:18)
F#m Eb5 D

(00:31)
A F#m D A

(00:50)
AMy (x02220@1)father had dementia
C#mHe (x13321@4)lied in bed for months
F#mOnce (244222@1)in a while he'd call me
        DmAnd (xx0231@1)ask me to fly down
BmI (x24432@1)told him that I'd love to
      DBut (xx0232@1)I had things to do
                   A (x02220@1)            A/Ab (402220@1)  F#mAnd (244222@1)so he died without his son
  Bm (x24432@1)                                           DI (xx0232@1)heard about it drunk after a show

(1:14)

AMy (x02220@1)mother battled cancer
C#mFor (x13321@4)over seven years
F#mI (244222@1)nursed her and I held her
          DmWhen (xx0231@1)time was running out
       BmThe (x24432@1)night before she left me
              DI (xx0232@1)drank scotch all night
                                     A (x02220@1)     A/Ab (402220@1)          F#mAnd (244222@1)thanked her for everything she'd done
Bm (x24432@1)                                              DRaising (xx0232@1)me alone wasn't much fun

(1:37)

ASo (x02220@1)Dad I can forgive you, 
       EBut (022100@1)I'll never forget, 
Bm (x24432@1)                                                DMonths (xx0232@1)I wouldn't see you and when I did You'd be 
Aout (x02220@1)with your friends all night
EAlone (022100@1)and only nine
  BmI (x24432@1)watched the outer limits
           DWhile (xx0232@1)scared out of my mind
AI (x02220@1)wonder if you felt the same
                                              A/AbThe (402220@1)days before you died
F#mI (244222@1)wonder if you even knew

Why I wouldn't come around
BmI (x24432@1)bet if you had been there, 
                                                  
There wouldn't be this song

A (x02220@1)     A/Ab2006 (402220@1)
F#mgoodbye (244222@1)parents
                       DFor (xx0232@1)once sincere
                               A2006 (x02220@1)my orphan year

(2:32)
REPEAT INTRO

so yeah thats about it.