What do you do if you are stuck on Star wars knights of the old republic 2 Sith lord where the Sith are on the moon duxn

If this is the movie, right after Queen Talia gets killed by Vaclu Soldiers, and well I decided to take Vaclu's side and kill the good jedi, then you do this. I looked into my Xbox hard drive to see if a saved game saved on the game but not the hard drive. I just backed myself up in case I had to look at the hard drive. Then my game wouldn't work on the Auto Save of landing on Dxun, so I beat the good jedi by using a double bladed lightsaber, always having on my best shield, using a ton of medpacs, and I used the power drain life a lot and I used other force powers. When I beat this the game didn't glitch on the way to Dxun the second time I beat the good jedi.