Hang in there pal! If you feel like you're not contributing enough to the group, cross-class in mantra from the monk set!

Don't worry though, most of the damage you deal is frontal loaded! When everyone's DPS is up to par and the gear is better, Doom Spike becomes AMAZING aoe damage. You might run out of TP, but that is what invigorate is for! My recommendation? Single target until you have 5 or more targets to AoE!

Seriously though, I felt the same way until everyone's gear started getting better. Mobs die a lot faster, so that means the guys who do the most frontloaded DPS will be on top!

tldr; just wait