For your level, this is the Mutilate spec you should use:
42/13/7. From there, you can fill in where ever the hell you please, but the core soloing talents are there. Use Wound poison on both daggers, and you shouldn't have any problems. If you're still getting half your health bar nipped off on single pulls, you're doing something horribly, nefariously, catastrophically wrong.
If you don't like Mutilate, this is a good Combat spec for your level:
6/51/5. Just fill in the rest of the Assassination tree as you level up. You'll still want Wound poison on both weapons here, but you want a slow weapon in your mainhand, and a fast weapon in your offhand (i.e. that mace you're using in the OH now has got to go). The points in CQC can be moved to the weapon spec that suits your weapons at the time.
And before anybody jumps in with "zomg riposte sucks!1!11one", it's a cheap CP and a kickass leveling talent. Totally worthless in a group/raid environment, but invaluable for grinding levels.