Some Help PleaseFollow

Here is my armory

http://www.wowarmory.com/character-sheet.xml?r=Eitrigg&n=Risentank

Currently my rotation while tanking is DnD, Death Grip, Icy Touch, Plague Strike, Blood Strike, Pestilence, Then depending on mob and heals either Scourge Strike or Death Strike

I really have no problem holding threat if I am the only DK in the group (rare), So a question for all the experienced DK's out there, is my build going wrong? I am trying to be a hybrid atm with good dps for leveling but good health for Tanking. Thanks in advance for any help everyone gives