I can help:
Have fun
I guess if all else fails and you're getting frustrated with being unable to complete it: I'd suggest probably lowering the game difficulty for that battle, hopefully that will help you.
Flame, run away.... repeat until that Draugr is truly dead. If the Draugr does not have a Bow and Arrows, it is possible to jump from the tomb to the ledges and cook it from safety.
If Tolfdir has not caught up to You the Draugr You are facing is just difficult at a lower level.