I am doing the Shrine of Azura with the black star. I can't seem to beat Dremora. I am at level 20. It that too early to try this quest? I have the broken black star and have heard Azura and then put in the star to battle Dremora.
What do I need to beat this dude?

potions did help me a lot
especially health potions and fire/ shock resist

I've never done the white-star option for the quest, but I've generally had some difficulty doing the dungeon and the black star quest in the low 20's. Best bet is to stock up on the relevant potions you need as well as "save" a level up as a full heal in the fight.