If you are in level appropriate gear, meaning you are in lvl 61 or lvl 63 gear when doing those quests, and are dying really fast then I would say there is something wrong with the quest. You shouldn't need to be in lvl 70 or 80 gear for a lvl 61 quest. I would say try to pull one enemy at a time. Make sure you are using your trance to have instant casts. Other than that all SMN has is DoTs and you need to have those up or Ruin suffers.