Not worth watching

As the title says, the male lead travel to the past. The people from 2012 look exactly like themself in 2017.
In the drama, if you save someone from death, someone else has to die, but on the last travel of the xiao yu, it’s the future him who sacrifices himself to save his 2011 version of him… I can’t explain it well but the story just doesn’t make sense and is contradictory.
The story is very confuse and at the end there’s another short story on time travel, but there’s no explanation on how the guy got his time machine.