Hi im Śres of Stonemaul

Link: The World of Warcraft Armory

I need help on my char i seem not to be doing the dps i should be doing i have a gear score of 2180 and i only do 2.8max on dummys with everything sunder and all. my rotation is

Rend, MS, Slam, Execute and Overpower and Bladestore with trinket when its up and keep rend up and sunder armor. what should i do i wanna get more dps but i just cant seem to push that much can someone help please?