soooooo my original time was 12:15 but somehow it was changed to 12:57 why?

This is because of the Autosplitter you used. Look back in your video. In the Sub Worlds your livesplit goes at 0.5x the speed. I.e you are going twice as fast then usual meaning your time is much faster than it should of been.

Check this video for the right Autosplitter. It doesn't have the splits but it does the most important part which is getting rid of loads.

thanks man