It is the song played during the credits of the spongebob special "have you seen this snail"

Some words I can remember:

I wondered how things went so wrong
I turned around and he was gone

Lyrics To "The Gary Song"
Sung by Stew

Verse 1

Gary now I know. I was wrong, I messed up, and now your gone. Gary I'm sorry I neglected you oh I never expected you to run away and leaving this Empty.. your meow right now would sound like music to me please come home because I miss you Gary.

Background: Gary, come home...

Gary, come home...

Background: Gary, come home...

Verse 2

Gary can't you see I was blind I'll do anything to change your mind. More than a pet you're my best friend too cool too forget, come back Cause' we are family and forgive me for making you on the roam now my heart beats like the saddest metronome. Somewhere I hope you're reading my latest three-word poem: Gary, come home..

Background: Gary come home...

Gary, come home

Background: Gary, come home...

Gary, come home

Background: Gary come home...

Gary, come home

Background: Gary come home...

Ahh
Gary, come home
Gary, come home
Gary, won't you come home? (edit)

No that's the song in the episode I was looking for the song in the credits but thanks so much for trying...

The most I could find was a snippet:

I wonder how things went so wrong
I turned around and he was gone...
Where's Gary?
Now I"m searching for a little sign,
a trail of sign he left behind
'cause I'm so lonely all the time
Oh where has Gary gone?

The song is located on the CD, "best Day Ever", track 8.