You should have no trouble holding agro to like 3-4KDps even in your current gear with that mace so something is wrong. Okay lets do this by the sequence.
1. Do you have Righteous Fury on?
2. Fix your spec
the long version: http://maintankadin.failsafedesign.c...pic&start=1470
One version of a 53/18 build: http://www.wowhead.com/?talent#sZV0t...fdxfMh0c:Gp0Vm
3. Next you need to do 969 rotation here is a video explaining http://www.youtube.com/watch?v=MZyOoMKtREI
4. Finally you need to gem and chant your gear properly http://maintankadin.failsafedesign.c...m-enhancements
Start with that and see how you go.
** Remember Warcraft players fail in directions you never thought possible.