By far TOO UNREALISTIC.
Internal consistency and following its own logic is needed even in a fantasy. The reason the guy was destroyed when he touched his other self was about the rule established in this story that the same object cannot touch itself.
WELL GUESS WHAT??
Did the person who wrote this script ever learn BASIC HUMAN ANATOMY?? is it not VERY common knowledge that we shed our skin cells and grow new ones EVERY MONTH?? There was a 12 year time difference between the 2 versions of the character that destroyed itself yet after just one month a person's skin is completely replaced! it is NOT the same matter.
It would be like a car touching an earlier version of itself AFTER getting all of the metal replaced at an auto shop first, even if it looked the same it would NOT be the same matter.
Also, there is the grandfather paradox issue here. If the older version kills the younger version of the same person its not a paradox for the death of the OLDER one but the YOUNGER one dies too making it impossible for himself to get older and then go back to kill the younger one. For example if I went back in time and killed my five year old self then that younger version of me cannot grow up to go back in time and kill himself.
Plus at the end he has know memory of this "alternate timeline". He has a wife waiting for him but no memories of it. How is that a happy ending? it means he will freak his family out by having no memory of their marriage, he wont even recognize his own daughter. What should have happened is his memories should have instantly filled in and made him unaware of the rest of the story and the tragedies kind of like what happened to the crew in the Star Trek the Next Generation episode "Yesterday's Enterprise" to every character except for the mysterious Guinan.