to me, the issue is that he is in this self imposed "witness protection program" that was his exit on breaking bad. the paranoia and fear is eating him up. He didn't know if his DL and/or SSN would pass a light review as part of his ER stay. Then, he was paranoid about the cab driver who spent time in new mexico. Did he know Saul? Its eating him up.
the song playing was my echo, my shadow and me by the Ink Spots
We three, we're all alone
Living in a memory
My echo, my shadow and me
We three, we're not a crowd
We're not even company
My echo, my shadow and me
What good is the moonlight
The silvery moonlight
That shines above?
I walk with my shadow
I talk with my echo
But where is the one I love?
We three, we'll wait for you
Even 'til eternity
My echo, my shadow and me
We three, we're all alone
Seem like we living in a memory
That's my echo, my shadow and me
We three, we ain't no crowd
Fact is we ain't even company
That's my echo, my shadow and me
You know,…
He's lonely, miserable, and in great fear. I suspect, in the final episode, he'll do something really dumb to be exposed as Saul after living as someone else and working for minimum wage at Cinnabon for years. Saul will decide it is better to die than to live that solitary life. The story lines of Saul, Kim, Mike, Nacho, Gus, will all be combined down the road in some cataclysmic action by Saul. we know the demise of Mike, Nacho and Gus though.