Noone said Multiboxing is easy, except those who hate multiboxing in nerdrage.

You are no noob Just keep on trying, Azjol Nerub is one of the hardest Instances to go, in special for melees, if you got blue / green equip. Go Utgard Keep and Nexus. First. Then Drak Tharon. Be sure to focus the small mages on your way to the first boss