i would say nehrim is a bit or a lot harder than oblivion, however i found that enjoyable. in oblivion i didn't really have cause to run from a fight, unless i treaded on carelessly. just out of curiosity, what's your character like? are you more like a skirmisher, battlemage, a melee fighter, etc? you might try fighting evasively, hit & fallback or sidestep, save heavy blows for when your opponent is off-balance. or attack from ambush (my preferred way to kill things), stealth can be a large deciding factor, even if you can't get a sneak attack usually you can still land the first blow, sometimes that can be enough. Healing is also an important thing to remember as well. Well I guess that’s all fairly well known. But the only thing I can really add, evading blows is better than trying to block them (IMHO), assuming you can evade a particular hit, if you can’t that is when you block. Well that’s about all I can think of.
---edit
at first it is a bit hard... some might say too hard, i don't though. you just need to be very careful. some people even think that when you get your character going it gets to easy, my first character is level 51 atm, do i think the game is to easy? i guess, but i view it as a reward for creating a hardened character.