DR was kind of mentioned, so on top of other advice you were given, I would make sure you take Barbarian Damage Reduction I and II. 2/- DR may not seem like much, but when you are getting hit by multiple mobs, it can add up quickly. That and barbarians get 1/- DR at level 2, then they don't starting getting it again, until around your level. So over the next few levels, your automatic DR will go up, and that will start helping more as well. DR is a barbarian's AC, and every little bit added is useful unlike AC is for most people.