DRK is no WAR, but DRK in full Cryptlurker gear should have enough sustain between TBN and mitigation abilities to handle most pulls easily in any dungeon, outside of a healer making a mistake or you blowing Living Dead early and the healer not being ready for it.

As mentioned earlier also, if _everyone_ is at 10%, that's on you (for not tanking everything) or them (for not staying out of AoEs). As a healer, a regen should be enough on DPS for trash packs to handle the occasional mistake, but DPS has self heals of their own to handle those as well.

Maybe you actually had a bad healer, but without any sort of context and judging by the implication that this happens to you extremely frequently, I'm leaning toward the healer not being the issue.