Character sheet can be found here

Guild has moved onto trying 10 man hardmodes in Ulduar and I'm really struggling to maintain aggro. Currently dualspecced Survival/UA, have used DW build for a while and maxxed at about 6k TPS with that at best. I prioritise on SS/Rev, Use Devestate fairly regularly and spam HS as rage allows, which isn't as much as I seem to need. With the survival build I'm struggling to maintain 5k TPS and I have DPS that can pull that.

Tonight was a downer: I successfully MT'd XT-002 (sole tank), Kologarn (meh), Auriaya and Hodir, OT'd Freya, ran the gauntlet quick enough in Thorim to put us into hard mode (oops ) and OT'd Mimiron tanking the head in phase 3. But on IC hardmode I struggled that much to stay on top of Brundir I lost aggro on Molgeim causing healers to die. Needless to say my name is mud and I'm quite frustrated.

I know I have a problem generating sufficient threat, I never had the problem before Ulduar, I've tried a few things and now I'm stuck; anyone got any tips? Or am I just crap at pushing buttons?