I did this quest at lvl 21 with only a little trouble. I just made sure to kill the adds as soon as he spawned them. You can overload them and then one shot them before they get back up. Other than that, make sure you are gearing Khem Val and that he has his defensive stance turned on. Khem almost tanked the boss the whole fight. He died right before I finished the boss off. If this don't work, maybe try coming back in a couple of levels.