Rotation's fine, gear just needs upgrading. Frost doesn't shine until you start getting Tier pieces + Sigil of Awareness. Hit 2k DPS on heroics and you'll be ready for Naxx.
Pretty much all I can say. Suggestion would be to go with dual wielding to start off, preferably with 32/39, and then when you start getting at least the two piece tier 7, you could go back to Frost and see good numbers.