Help on DPS

http://armory.warmane.com/character/...ecrown/summary There is my armory. I started playing wow 2 months ago and im so confused on DKs. I really don't understand where i am doing wrong. I got the gears i can, i did the rotations correctly, did talents exactly same with guides. Its really awkward and shameful to say but even people with 4.9K-5K GS getting better DPS than me... Where i am doing wrong? Spec, Talents, Gears, Rotation. Can somebody guide me which spec i should go for pve and how? Last 1 month wasn't changing. Can't find better gear, can't get more dps etc. Where i am doing wrong and what sould i do now?

For starters, you don't have "the gears" - you're running 3 tank items and 2 INTELLECT ONES (intellect is a stat you should NEVER use because it gives you absolutely nothing) and 1 PvP item which is terrible for PvE.
You have no enchants, half of your gems are bad (read guide for which ones you need) and you're running a wrong subtree in talents (instead of blood subtree, go into Frost).

Read this: http://forum.warmane.com/showthread.php?t=344509
and read his Unholy guide: http://forum.warmane.com/showthread.php?t=349829 and tanking guide: http://forum.warmane.com/showthread.php?t=349830
And when I say read, I mean read ALL OF IT CAREFULLY and keep reading until you understand it.

Get enchants on all items. Change bad gems.
Buy better trinkets: Mark of Supremacy OR Mirror of Truth (depending on your stats - if you have enough hit rating you'll take Mirror) AND Herkumi War Token ASAP
Replace wrist with Titanium Spikeguards crafted from Blacksmithing
Replace belt with Belt of the Titans crafted from Blacksmithing
Replace boots with Hellfrozen Bonegrinders crafted from Blacksmithing
Replace cloak with Ice Striker's Cloak from Leatherworking or buy Emblem of Frost cloak Might of the Ocean Serpent
Replace legs with Legplates of Painful Death crafted from Blacksmithing or the Scourgelord Legplates from Emblem of Frost vendor or the set legs Koltira's Legplates of Conquest from Emblem of Triumph vendor, depending on how you stand with gold and emblems

Or you can grind FoS/PoS/HoR heroic for items that fit those slots (keep in mind they'll be slightly worse than the ones I linked above). Also don't forget which stats your class needs when you're farming them.

Thank you!