I'm not a fan of your spec and I think you're doing something wrong single target wise...
As far as your spec is concerned, I'd recommend
http://www.wowhead.com/?talent=j0xZGxezccdMhRVsotcx. It gives you 6 points that you can spend wherever, but gives you some of the necessities. I've never had a problem with this frost build, but it's all preferences anyway.
Why use rune strike when frost strike is better? Why use Obliterate when Deathstrike is so much better (in that it makes it easier on your healer)?
It's also Possible you're focusing on using too many aoe abilities at the expense of all else...I might also add that Death and Decay, until the patch, is THE ability (imo) to gain threat. Granted, it takes micro management. But then this class is all about micro management.
Again, I've never had problems with this build, and I apologize, but I'm currently dps specced on the armory, otherwise I'd link it.