I would have explored how the world has changed. Maybe include some sci-fi thing. How the character is struggling to cope up. I am not suggesting you should have overdone it. And finally you should have written the earlier part in present tense.
See I am not a successful writer or anything. These are just my observations. Everyone has their own style. This is yours. You will get there by trial and error.
Actually, you nailed it. You spotted where the story needs to build up. Your comment as a reader matters. I wIll surely work on it. It only started as a facebook post.
As for the first part, it has to be in the past tense because i am given a second chance and brought back to restart again