Have you tried the Poison Weapon skill? It will also work on a bow, if you want to try hit and run tactics. The passive Stun skill is handy for a melee warrior (though it needs to be at level 4 or 5 before it starts having a significant chance of being triggered), and can help quite a bit if you get the first hit in and keep swinging.
A warrior can make any fight easy (to the point of being boring):
If a warrior drinks a shadow potion and uses their spin attack near (but not directly on) a creature, they will hit it without turning visible or provoking a counter attack.
Have you checked merchants for better equipment? Even just more
restoration potions would help, if it can not kill you outright in a couple of hits.
You could always leave and return when you've gone up a couple levels. That is what I did, since he is fairly tough if you do that series of quests relatively early.
The suggestions in the following topic will work for any strong opponent.
Chasing Josie... (Spoilers) techniques for defeating Josephine
