My interpretation!
I think this is about ghosts or spirits who are living in hell and darkness and can't go through the light because they are trapped in their past and can't accept their death because they are consumed by strong feelings of guilt, anger, love, attachment, etc. Simon is a trapped soul because he can't accept his death or what happened and even when he tried to change how things could have happened, it was like a merry go round that ends up in the same page where it started. And even though he, in his mind changed the years to 20:00 to 20:02, it went back to the beginning. I think he has been doing it over and over again trying to change events or facts in his mind hoping it will change things. He is dead and bad things happened...he needed to accept the facts and forgive himself in order to see the light and travel peacefully to the afterlife.
The title "The I Inside" means he is trapped by choice. He is inside and refuses to come out or let go of what has happened.