This was a movie I saw on late night television 3 or 4 years ago, I don’t remember the plot in full, but I remember a number of events, which may be out of order, that I will now recount:

The protagonist is watching television when he sees himself on a talkshow, the talkshow-him directly addresses him.

The protagonist goes in to work, he has his own office, but it’s got a glass wall/door that his desk faces towards. The coworker in the office directly across from him sits there staring at him constantly. In order to avoid the gaze of his coworker, the protagonist plasters the window(s) of his office with newspaper clippings. I believe he also finds a “how to build a nuclear shelter” manual on/in his desk in this scene

At some point he builds the nuclear shelter described in the manual he obtained at work. This scene felt an awful lot like he was digging a grave instead of a nuclear fallout shelter, but that may have just been me.

The protagonist hears ticking coming from the wall of his dining room (or some room in his house), and smashes through the wall to find an alarm clock along with newspaper clippings (although I’m not sure about the newspaper clippings). It is later revealed that the creepy coworker who was staring him down put a/the clock in the wall “after” the protagonist had smashed through it, and plastered over the hole, but because time is wibbly wobbly this was the cause of the clock’s existence