I was thinking about it more after the EP. Maybe his past trauma led to a 50 first dates/shutter island mixed type mental state...and him falling off the pier/getting pushed made things worse.
The thing that Im still hung up on a tad is the sequence with the blank disk at the end. He hacked himself and found no records...then found the disk unlabeled and thought it was him..but it was Mr. Robot. This is why I thought it was possible that Mr Robot is real but Elliot is not. To Elliot, there is still no proof that he is real outside of the pictures of the family and the shoddy narration and interaction with other characters. Its a wild long shot..but I suppose its conceivable that Mr. Robot created Elliot (dead child?) as the imaginary friend once upon a time and perhaps tried to imagine how his child would have grown up and lived his life had he survived. Mr. Robot technically started fsociety and had his daughter join off the top but it took trouble for him to get Elliot along for the ride (non-existant?). Its common for parents to psychologically live vicariously through their children so its not impossible for this to be their angle after Robot went through insanity and other mental illnesses that led to him re-creating his son as a friend and then wishing he could be young again or that he had such high hopes for his son etc etc.
Mr. Robot has now met with Tyrell and it wasnt their first meeting (and Elliot had met with Tyrell three times before). Elliot, in all meetings, never disclosed any motives or indications he was in fsociety, yet Tyrell was aware of the cancer angle (when he talked to his wife about it). On the other hand, it is possible that Elliot had to go full blown Mr. Robot status in meeting Tyrell previously because of the increased pressure and the need to be an "adult" in such important meetings...but idk.