First of all, shadow focus is 3% hit and not 6% that means that you are only around 10% hit rating?, think you have got the numbers confused its 3% hit and 6% reduce mana cost of you shadow spells... and that really not good, and thats with ur racial. You will need between 16% to 17% if you really want something to happen.
And spriests arn't really a main dps in raids, like rogues, hunters, locks, paladins (in this patch) and so on... well im not saying it is not possible for a spriest reaching 5k dps, i've seen alot of them do it.
Plus change your pvp gear to some pve gear that can do the trick also, like you get more mana from replenishment and so on and that means that you can keep on going longer with out interupting your dps cycle in fights wich equals more dps.
And a little tip, reroll undead

Devouring plague helps alot in my own experience...