When I have tanked it on my pally I think the taunting was at 3 stacks as soon as the tanks old stacks wore off.
But it sounds like you have some serious issues with suboptimal dps.
If I were you I'd go over the dps macros and make sure they are as good as they can be.
All my dps characters were doing more dps than that before hitting 4k gearscore.