I read this as part of The Time Traveller’s Almanac, edited by Ann and Jeff VanderMeer.
Justin Kloster, the main character, has boyish looks despite being 40 years old. Then we learn that he is something of a genius when it comes to computers, and has figured out that he might be able to use superstrings and VR to time travel. He is also a divorcee who is really messed up about losing his wife. So he decides to travel back in time to patch things up.
At first one’s impression of Justin Kloster is that he’s a pretty pathetic specimen of a human being. His divorce took all the wind out of his sails and he can’t even do an evening out with his friends. Granted, he’s pretty obsessed about getting the time travel to work. I’m not sure that picture improves when he actually does go back in time.
This short story is well written, and vivid in its depiction of Kloster’s life and whereabouts. The ending was surprising, but I suppose satisfying and positive, given the general tenor of the rest of the story.