need an answer

So I've gotten my first class to 100. I'm at iLvl 627 which means I'm locked out of LFR BRF, and I've already run Highmaul for the week. Every time I look for the World Bosses, the only groups that are ever available are for Rukhmar and only Rukhmar, and I already helped kill him this week.
The result is that I've started levelling a second toon. I ended up with an Affliction Lock and I've gotten it to dungeon level but I feel totally useless in actually participating in dungeons. I basically can't help with any of the small mobs because so far they all just die before I finish channelling anything.should I feel useless as a low level affliction lock?
The result is that I've started levelling a second toon. I ended up with an Affliction Lock and I've gotten it to dungeon level but I feel totally useless in actually participating in dungeons. I basically can't help with any of the small mobs because so far they all just die before I finish channelling anything.should I feel useless as a low level affliction lock?