Dark Matter by Blake Crouch

Dark Matter is based on theories of the multi-verse, multiple universes. Imagine: You’re a happily married guy, with a pretty wife, handsome son. Life is good. You take a walk with the intent of buying ice cream. Somebody attacks you from behind, throws you into a car. You’re stripped naked, your neck is punctured with a knock-out drug. You wake on a gurney and everybody is glad to see you, glad that you made it back. But, there’s no wife, no kid, everything about your existence has changed. You’re now a successful scientist. You invented a transport system that allows you to traverse multiple universes.

There is more than one ‘you’. But … really only one ‘you’. The protagonist remembers his other self, and struggles sprinkle the pages with his desperate fight to go home. But, he is home. But, he’s not. Got it?