The Coffee Pony

It was basically about the Doctor wandering through his confession dial repeatedly asking for help from a non-speaking hallucination in the form of Clara and talking to said hallucination throughout the entire episode via monologuing and realizes that to escape he has to get through a 10 foot thick wall made of a material made of a rock stronger than Diamond and to get through it he punches it a couple of times, lets the monster kill him, push some kind of magical reset button through which h...

through which he repeats the same adventure with no memory of what transpires and does the same thing over and over again over the course of billions of years eventually punching the wall enough times to break through it.

So a repeat of the same thing till the doctor finally cracks through the wall. I wonder if it's cause Doctor was going insane or something?