Did you have Defiance up?
If you don't you will lose hate really quickly.

I usually pull w/ Tomahawk > Overpower > Overpower > start my first rotation. Flash in between as needed. I also cycle through mobs as needed.
For Overpower you must make sure that the mobs are in front of you. For Flash make sure the mobs are around you because it is centered around you so you can't target a mob 30yalms away and use flash to get hate.

Sometimes you will get healers who don't like to use Protect or Stoneskin because they feel it is useless. Personally, I think they don't don't use those skills because they are lazy but that's neither here nor there. Just do your best to ignore those types of situations even though they can be annoying.