You should be focusing on getting into Heroics/ Heroic Dailies, and Raids. Even a "poorly geared" warlock can post 2.2k+. I know, less than Epic'd out, in Heroics my build(s) perform. So will yours.
The biggest disadvantage you have is gear based, and those 3 points in Affliction for Suppression. Although it helps you reach the hit needed to really perform, its not going to get better until you grab some more gear that has +Hit/+Crit on it. Remember for an 80 lock, destro spec'd, without Suppression maxed, your hit cap it 17%-ish. I believe a Simcrafter or Theorycrafter on EJ can give you the actual number, its close to 445.
Buy your badge gear, run in some 10man ToC groups, and 10man Onyxia. They aren't hard. And lastly, avoid gear nazis that think you need a specific gear score or set to raid. Know your class, and be chanted/inscripted/spec'd/gemmed/glyphed/arcanum'd into it, and know your rotation(s). Don't hesitate to get Focus Magic from a Mage or snag up a Boomkin for 5% crit increase.
Consider using this for gemming = Yellow: Reckless Ametrine (Orange Gem)
Red: Runed Cardinal Ruby
Blue: Purified Dreadstone (Purple Gem)
Plenty of other warlocks out there are rocking the dps charts. Just focus on learning how to spam your rotation and filler spells and you'll see the biggest differance. Good Luck!
